using System;
using System.Collections.Specialized;
using System.Text.RegularExpressions;
/*
* (c) Craig Dunn - ConceptDevelopment.NET
* 12-June-04
*
* To use:
*    string encoded = ExtendedHtmlUtility.HtmlEntityEncode ("test string with Unicode chars and & < > é");
*    string decoded = ExtendedHtmlUtility.HtmlEntityDecode (encoded); // "string with &amp &lt; &gt; &eacute;"
*
* More info:
*    http://users.bigpond.com/conceptdevelopment/localization/htmlencode/
*/
public class ExtendedHtmlUtility
{
    /// <summary>
    /// Based on the 'reflected' code (from the Framework System.Web.HttpServerUtility)
    /// listed on this page
    /// UrlEncode vs. HtmlEncode
    /// http://www.aspnetresources.com/blog/encoding_forms.aspx
    ///
    /// PDF of unicode characters in the 0-127 (dec) range
    /// http://www.unicode.org/charts/PDF/U0000.pdf
    /// </summary>
    /// <param name="unicodeText">Unicode text</param>
    /// <returns>
    /// &amp; becomes &amp;amp;  (encoded for XML Comments - don't be confused)
    /// 0-9a-zA-Z and some punctuation (ASCII, basically) remain unchanged
    /// </returns>
    public static string HtmlEntityEncode(string unicodeText)
    {
        return HtmlEntityEncode(unicodeText, true);
    }

    /// <summary>
    /// 
    /// </summary>
    /// <param name="includeTagsEntities">whether to encode &amp; &lt; and &gt; which will
    /// cause the entire string to be 'displayable' as HTML. true is the default value.
    /// Setting this to false will result in a string where the non-ASCII characters
    /// are encoded, but HTML tags remain in-tact for display in a browser.</param>
    /// <returns>
    /// 0-9a-zA-Z and some punctuation (ASCII, basically) remain unchanged,
    /// everything else encoded
    /// </returns>
    public static string HtmlEntityEncode(string unicodeText, bool encodeTagsToo)
    {
        int unicodeVal;
        string encoded = String.Empty;        // StringBuilder would be better - but this is simpler
        foreach (char c in unicodeText)
        {
            unicodeVal = c;
            switch (unicodeVal)
            {
                // comentarios en lo que sigue
                //case '&':
                //    if (encodeTagsToo) encoded += "&amp;";
                //    break;
                //case '<':
                //    if (encodeTagsToo) encoded += "&lt;";
                //    break;
                //case '>':
                //    if (encodeTagsToo) encoded += "&gt;";
                //    break;
                default:
                    //anterior al 12/07/2013, ver abajo lo nuevo
                    ////////if ((c >= 0x0001) && (c <= 0x007E))        // (c >= ' '), lo cambié por 0x0001
                    ////////    // el cambio fue porque viene, p. ej.: chr(10) como separador y debe conservarse
                    ////////{ // from 'space' to '~tilde' hex 20-7E (dec 32-127)
                    ////////    // in 'ascii' range x30 to x7a which is 0-9A-Za-z plus some punctuation
                    ////////    encoded += c;    // leave as-is
                    ////////}
                    ////////else
                    ////////{ // outside 'ascii' range - encode
                    ////////    if (c != 0xA0)
                    ////////    {
                    ////////    encoded += string.Concat("&#"
                    ////////        , unicodeVal.ToString(System.Globalization.NumberFormatInfo.InvariantInfo)
                    ////////        , ";");
                    ////////    }
                    ////////}

                    // nueva versión, a partir de lo visto en RSS (12/07/2013):
                    if (((c >= 0x0020) && (c <= 0x007E)) || c == 0x000A || c == 0x000D)        // (c >= ' '), lo cambié por 0x0001 en página

                    // el cambio fue porque viene, p. ej.: chr(10) como separador y debe conservarse
                    { // from 'space' to '~tilde' hex 20-7E (dec 32-127)
                        // in 'ascii' range x30 to x7a which is 0-9A-Za-z plus some punctuation
                        encoded += c;    // leave as-is
                    }
                    else
                    { // outside 'ascii' range - encode
                        if ((c != 0xA0) && (c > 0x007E))  //los caracteres menores de 20 Hexadecimal no los procesa (ver el IF de arriba)
                        {
                            encoded += string.Concat("&#"
                                , unicodeVal.ToString(System.Globalization.NumberFormatInfo.InvariantInfo)
                                , ";");
                        }
                    }

                    break;
            }       // switch
        }   // for each   
        return encoded;
    } // HtmlEntityEncode

    /// <summary>
    /// Converts Html Entities back to their 'underlying' Unicode characters
    /// </summary>
    /// <param name="encodedText">Text containing Html Entities eg. &amp;#1234; or &amp;eacute;</param>
    /// <returns>
    /// &amp;amp; becomes &amp;  (encoded for XML Comments - don't be confused)
    /// 1-9a-zA-Z and some punctuation (ASCII, basically) remain unchanged
    /// </returns>
    public static string HtmlEntityDecode(string encodedText)
    {
        return entityResolver.Replace(encodedText, new MatchEvaluator(ResolveEntityAngleAmp));
    } // HtmlEntityDecode


    /// <summary>
    /// Converts Html Entities back to their 'underlying' Unicode characters
    /// </summary>
    /// <param name="encodedText">Text containing Html Entities eg. &amp;#1234; or &amp;eacute;</param>
    /// <param name="encodeTagsToo">Include angles and ampersand &lt; &gt; &amp;</param>
    /// <returns>
    /// &amp;amp; becomes &amp;  (encoded for XML Comments - don't be confused)
    /// 1-9a-zA-Z and some punctuation (ASCII, basically) remain unchanged
    /// </returns>
    public static string HtmlEntityDecode(string encodedText, bool encodeTagsToo)
    {
        if (encodeTagsToo)
            return entityResolver.Replace(encodedText, new MatchEvaluator(ResolveEntityAngleAmp));
        else
            return entityResolver.Replace(encodedText, new MatchEvaluator(ResolveEntityNotAngleAmp));
    } // HtmlEntityDecode


    /// <summary>
    /// Static Regular Expression to match Html Entities in encoded text
    /// Looking for named-entity, decimal or hexadecimal formats
    /// http://www.w3.org/TR/REC-html40/charset.html#h-5.3.1
    /// http://www.i18nguy.com/markup/ncrs.html
    /// http://www.vigay.com/inet/acorn/browse-html2.html#entities
    /// </summary>
    private static Regex entityResolver =
          new Regex(
            @"([&][#](?'decimal'[0-9]+);)|([&][#][(x|X)](?'hex'[0-9a-fA-F]+);)|([&](?'html'\w+);)"
          );

    /// <summary>
    /// Regex Match processing delegate to replace the Entities with their
    /// underlying Unicode character.
    /// </summary>
    /// <param name="matchToProcess">Regular Expression Match eg. [ &#123; | &#x1F | &eacute; ]</param>
    /// <returns>
    /// &amp;amp; becomes &amp;  (encoded for XML Comments - don't be confused)
    /// and &amp;eacute; becomes é
    /// BUT we dont modify the angles or ampersand
    /// </returns>
    private static string ResolveEntityNotAngleAmp(System.Text.RegularExpressions.Match matchToProcess)
    {
        string x = ""; // default 'char placeholder' if cannot be resolved - shouldn't occur
        if (matchToProcess.Groups["decimal"].Success)
        {
            x = Convert.ToChar(Convert.ToInt32(matchToProcess.Groups["decimal"].Value)).ToString();
        }
        else if (matchToProcess.Groups["hex"].Success)
        {
            x = Convert.ToChar(HexToInt(matchToProcess.Groups["hex"].Value)).ToString();
        }
        else if (matchToProcess.Groups["html"].Success)
        {
            string entity = matchToProcess.Groups["html"].Value;
            switch (entity.ToLower())
            {
                case "lt":
                case "gt":
                case "amp":
                    x = "&" + entity + ";";
                    break;
                default:
                    x = EntityLookup(entity);
                    break;
            }
        }
        else x = "X";
        return x;
    } // ResolveEntityNotAngleAmp()

    /// <summary>
    /// Regex Match processing delegate to replace the Entities with their
    /// underlying Unicode character.
    /// </summary>
    /// <param name="matchToProcess">Regular Expression Match eg. [ &#123; | &#x1F | &eacute; ]</param>
    /// <returns>
    /// &amp;amp; becomes &amp;  (encoded for XML Comments - don't be confused)
    /// and &amp;eacute; becomes é
    /// </returns>
    private static string ResolveEntityAngleAmp(System.Text.RegularExpressions.Match matchToProcess)
    {
        string x = ""; // default 'char placeholder' if cannot be resolved - shouldn't occur
        if (matchToProcess.Groups["decimal"].Success)
        {
            x = Convert.ToChar(Convert.ToInt32(matchToProcess.Groups["decimal"].Value)).ToString();
        }
        else if (matchToProcess.Groups["hex"].Success)
        {
            x = Convert.ToChar(HexToInt(matchToProcess.Groups["hex"].Value)).ToString();
        }
        else if (matchToProcess.Groups["html"].Success)
        {
            x = EntityLookup(matchToProcess.Groups["html"].Value);
        }
        else x = "Y";
        return x;
    } // ResolveEntityAngleAmp()



    /// <summary>
    /// For the 'hexadecimal' format &amp;#x233; we need to be able 
    /// to convert hex into decimal...
    /// Thanks for this method to
    /// http://www.c-sharpcorner.com/Code/2002/Sept/HexColors.asp
    /// </summary>
    /// <remarks>
    /// This method converts a hexvalues string as 80FF into a integer.
    /// Note that you may NOT put a '#' at the beginning of string! There
    /// is not much error checking in this method. If the string does not
    /// represent a valid hexadecimal value it returns 0.
    /// </remarks>
    /// <param name="hexstr">eg 00, 1A, ff, etc</param>
    /// <returns>eg. 0, 26, 255 (zero if the inputstring is NOT a valid hexadecimal)</returns>
    public static int HexToInt(String hexstr)
    {
        int counter, hexint;
        char[] hexarr;
        hexint = 0;
        hexstr = hexstr.ToUpper();
        hexarr = hexstr.ToCharArray();
        for (counter = hexarr.Length - 1; counter >= 0; counter--)
        {
            if ((hexarr[counter] >= '0') && (hexarr[counter] <= '9'))
            {
                hexint += (hexarr[counter] - 48) * ((int)(Math.Pow(16, hexarr.Length - 1 - counter)));
            }
            else
            {
                if ((hexarr[counter] >= 'A') && (hexarr[counter] <= 'F'))
                {
                    hexint += (hexarr[counter] - 55) * ((int)(Math.Pow(16, hexarr.Length - 1 - counter)));
                }
                else
                {
                    hexint = 0;
                    break;
                }
            }
        }
        return hexint;
    } //HexToInt



    /// <summary>
    /// Thanks to this site for the Entity Reference
    /// http://www.vigay.com/inet/acorn/browse-html2.html#entities
    /// </summary>
    private static string EntityLookup(string entity)
    {
        string x = "";
        switch (entity)
        {
            case "Aacute": x = Convert.ToChar(0x00C1).ToString(); break;
            case "aacute": x = Convert.ToChar(0x00E1).ToString(); break;
            case "acirc": x = Convert.ToChar(0x00E2).ToString(); break;
            case "Acirc": x = Convert.ToChar(0x00C2).ToString(); break;
            case "acute": x = Convert.ToChar(0x00B4).ToString(); break;
            case "AElig": x = Convert.ToChar(0x00C6).ToString(); break;
            case "aelig": x = Convert.ToChar(0x00E6).ToString(); break;
            case "Agrave": x = Convert.ToChar(0x00C0).ToString(); break;
            case "agrave": x = Convert.ToChar(0x00E0).ToString(); break;
            case "alefsym": x = Convert.ToChar(0x2135).ToString(); break;
            case "Alpha": x = Convert.ToChar(0x0391).ToString(); break;
            case "alpha": x = Convert.ToChar(0x03B1).ToString(); break;
            case "amp": x = Convert.ToChar(0x0026).ToString(); break;
            case "and": x = Convert.ToChar(0x2227).ToString(); break;
            case "ang": x = Convert.ToChar(0x2220).ToString(); break;
            case "aring": x = Convert.ToChar(0x00E5).ToString(); break;
            case "Aring": x = Convert.ToChar(0x00C5).ToString(); break;
            case "asymp": x = Convert.ToChar(0x2248).ToString(); break;
            case "Atilde": x = Convert.ToChar(0x00C3).ToString(); break;
            case "atilde": x = Convert.ToChar(0x00E3).ToString(); break;
            case "auml": x = Convert.ToChar(0x00E4).ToString(); break;
            case "Auml": x = Convert.ToChar(0x00C4).ToString(); break;
            case "bdquo": x = Convert.ToChar(0x201E).ToString(); break;
            case "Beta": x = Convert.ToChar(0x0392).ToString(); break;
            case "beta": x = Convert.ToChar(0x03B2).ToString(); break;
            case "brvbar": x = Convert.ToChar(0x00A6).ToString(); break;
            case "bull": x = Convert.ToChar(0x2022).ToString(); break;
            case "cap": x = Convert.ToChar(0x2229).ToString(); break;
            case "Ccedil": x = Convert.ToChar(0x00C7).ToString(); break;
            case "ccedil": x = Convert.ToChar(0x00E7).ToString(); break;
            case "cedil": x = Convert.ToChar(0x00B8).ToString(); break;
            case "cent": x = Convert.ToChar(0x00A2).ToString(); break;
            case "chi": x = Convert.ToChar(0x03C7).ToString(); break;
            case "Chi": x = Convert.ToChar(0x03A7).ToString(); break;
            case "circ": x = Convert.ToChar(0x02C6).ToString(); break;
            case "clubs": x = Convert.ToChar(0x2663).ToString(); break;
            case "cong": x = Convert.ToChar(0x2245).ToString(); break;
            case "copy": x = Convert.ToChar(0x00A9).ToString(); break;
            case "crarr": x = Convert.ToChar(0x21B5).ToString(); break;
            case "cup": x = Convert.ToChar(0x222A).ToString(); break;
            case "curren": x = Convert.ToChar(0x00A4).ToString(); break;
            case "dagger": x = Convert.ToChar(0x2020).ToString(); break;
            case "Dagger": x = Convert.ToChar(0x2021).ToString(); break;
            case "darr": x = Convert.ToChar(0x2193).ToString(); break;
            case "dArr": x = Convert.ToChar(0x21D3).ToString(); break;
            case "deg": x = Convert.ToChar(0x00B0).ToString(); break;
            case "Delta": x = Convert.ToChar(0x0394).ToString(); break;
            case "delta": x = Convert.ToChar(0x03B4).ToString(); break;
            case "diams": x = Convert.ToChar(0x2666).ToString(); break;
            case "divide": x = Convert.ToChar(0x00F7).ToString(); break;
            case "eacute": x = Convert.ToChar(0x00E9).ToString(); break;
            case "Eacute": x = Convert.ToChar(0x00C9).ToString(); break;
            case "Ecirc": x = Convert.ToChar(0x00CA).ToString(); break;
            case "ecirc": x = Convert.ToChar(0x00EA).ToString(); break;
            case "Egrave": x = Convert.ToChar(0x00C8).ToString(); break;
            case "egrave": x = Convert.ToChar(0x00E8).ToString(); break;
            case "empty": x = Convert.ToChar(0x2205).ToString(); break;
            case "emsp": x = Convert.ToChar(0x2003).ToString(); break;
            case "ensp": x = Convert.ToChar(0x2002).ToString(); break;
            case "epsilon": x = Convert.ToChar(0x03B5).ToString(); break;
            case "Epsilon": x = Convert.ToChar(0x0395).ToString(); break;
            case "equiv": x = Convert.ToChar(0x2261).ToString(); break;
            case "Eta": x = Convert.ToChar(0x0397).ToString(); break;
            case "eta": x = Convert.ToChar(0x03B7).ToString(); break;
            case "eth": x = Convert.ToChar(0x00F0).ToString(); break;
            case "ETH": x = Convert.ToChar(0x00D0).ToString(); break;
            case "Euml": x = Convert.ToChar(0x00CB).ToString(); break;
            case "euml": x = Convert.ToChar(0x00EB).ToString(); break;
            case "euro": x = Convert.ToChar(0x20AC).ToString(); break;
            case "exist": x = Convert.ToChar(0x2203).ToString(); break;
            case "fnof": x = Convert.ToChar(0x0192).ToString(); break;
            case "forall": x = Convert.ToChar(0x2200).ToString(); break;
            case "frac12": x = Convert.ToChar(0x00BD).ToString(); break;
            case "frac14": x = Convert.ToChar(0x00BC).ToString(); break;
            case "frac34": x = Convert.ToChar(0x00BE).ToString(); break;
            case "frasl": x = Convert.ToChar(0x2044).ToString(); break;
            case "gamma": x = Convert.ToChar(0x03B3).ToString(); break;
            case "Gamma": x = Convert.ToChar(0x393).ToString(); break;
            case "ge": x = Convert.ToChar(0x2265).ToString(); break;
            case "gt": x = Convert.ToChar(0x003E).ToString(); break;
            case "hArr": x = Convert.ToChar(0x21D4).ToString(); break;
            case "harr": x = Convert.ToChar(0x2194).ToString(); break;
            case "hearts": x = Convert.ToChar(0x2665).ToString(); break;
            case "hellip": x = Convert.ToChar(0x2026).ToString(); break;
            case "Iacute": x = Convert.ToChar(0x00CD).ToString(); break;
            case "iacute": x = Convert.ToChar(0x00ED).ToString(); break;
            case "icirc": x = Convert.ToChar(0x00EE).ToString(); break;
            case "Icirc": x = Convert.ToChar(0x00CE).ToString(); break;
            case "iexcl": x = Convert.ToChar(0x00A1).ToString(); break;
            case "Igrave": x = Convert.ToChar(0x00CC).ToString(); break;
            case "igrave": x = Convert.ToChar(0x00EC).ToString(); break;
            case "image": x = Convert.ToChar(0x2111).ToString(); break;
            case "infin": x = Convert.ToChar(0x221E).ToString(); break;
            case "int": x = Convert.ToChar(0x222B).ToString(); break;
            case "Iota": x = Convert.ToChar(0x0399).ToString(); break;
            case "iota": x = Convert.ToChar(0x03B9).ToString(); break;
            case "iquest": x = Convert.ToChar(0x00BF).ToString(); break;
            case "isin": x = Convert.ToChar(0x2208).ToString(); break;
            case "iuml": x = Convert.ToChar(0x00EF).ToString(); break;
            case "Iuml": x = Convert.ToChar(0x00CF).ToString(); break;
            case "kappa": x = Convert.ToChar(0x03BA).ToString(); break;
            case "Kappa": x = Convert.ToChar(0x039A).ToString(); break;
            case "Lambda": x = Convert.ToChar(0x039B).ToString(); break;
            case "lambda": x = Convert.ToChar(0x03BB).ToString(); break;
            case "lang": x = Convert.ToChar(0x2329).ToString(); break;
            case "laquo": x = Convert.ToChar(0x00AB).ToString(); break;
            case "larr": x = Convert.ToChar(0x2190).ToString(); break;
            case "lArr": x = Convert.ToChar(0x21D0).ToString(); break;
            case "lceil": x = Convert.ToChar(0x2308).ToString(); break;
            case "ldquo": x = Convert.ToChar(0x201C).ToString(); break;
            case "le": x = Convert.ToChar(0x2264).ToString(); break;
            case "lfloor": x = Convert.ToChar(0x230A).ToString(); break;
            case "lowast": x = Convert.ToChar(0x2217).ToString(); break;
            case "loz": x = Convert.ToChar(0x25CA).ToString(); break;
            case "lrm": x = Convert.ToChar(0x200E).ToString(); break;
            case "lsaquo": x = Convert.ToChar(0x2039).ToString(); break;
            case "lsquo": x = Convert.ToChar(0x2018).ToString(); break;
            case "lt": x = Convert.ToChar(0x003C).ToString(); break;
            case "macr": x = Convert.ToChar(0x00AF).ToString(); break;
            case "mdash": x = Convert.ToChar(0x2014).ToString(); break;
            case "micro": x = Convert.ToChar(0x00B5).ToString(); break;
            case "middot": x = Convert.ToChar(0x00B7).ToString(); break;
            case "minus": x = Convert.ToChar(0x2212).ToString(); break;
            case "Mu": x = Convert.ToChar(0x039C).ToString(); break;
            case "mu": x = Convert.ToChar(0x03BC).ToString(); break;
            case "nabla": x = Convert.ToChar(0x2207).ToString(); break;
            case "nbsp": x = Convert.ToChar(0x00A0).ToString(); break;
            case "ndash": x = Convert.ToChar(0x2013).ToString(); break;
            case "ne": x = Convert.ToChar(0x2260).ToString(); break;
            case "ni": x = Convert.ToChar(0x220B).ToString(); break;
            case "not": x = Convert.ToChar(0x00AC).ToString(); break;
            case "notin": x = Convert.ToChar(0x2209).ToString(); break;
            case "nsub": x = Convert.ToChar(0x2284).ToString(); break;
            case "ntilde": x = Convert.ToChar(0x00F1).ToString(); break;
            case "Ntilde": x = Convert.ToChar(0x00D1).ToString(); break;
            case "Nu": x = Convert.ToChar(0x039D).ToString(); break;
            case "nu": x = Convert.ToChar(0x03BD).ToString(); break;
            case "oacute": x = Convert.ToChar(0x00F3).ToString(); break;
            case "Oacute": x = Convert.ToChar(0x00D3).ToString(); break;
            case "Ocirc": x = Convert.ToChar(0x00D4).ToString(); break;
            case "ocirc": x = Convert.ToChar(0x00F4).ToString(); break;
            case "OElig": x = Convert.ToChar(0x0152).ToString(); break;
            case "oelig": x = Convert.ToChar(0x0153).ToString(); break;
            case "ograve": x = Convert.ToChar(0x00F2).ToString(); break;
            case "Ograve": x = Convert.ToChar(0x00D2).ToString(); break;
            case "oline": x = Convert.ToChar(0x203E).ToString(); break;
            case "Omega": x = Convert.ToChar(0x03A9).ToString(); break;
            case "omega": x = Convert.ToChar(0x03C9).ToString(); break;
            case "Omicron": x = Convert.ToChar(0x039F).ToString(); break;
            case "omicron": x = Convert.ToChar(0x03BF).ToString(); break;
            case "oplus": x = Convert.ToChar(0x2295).ToString(); break;
            case "or": x = Convert.ToChar(0x2228).ToString(); break;
            case "ordf": x = Convert.ToChar(0x00AA).ToString(); break;
            case "ordm": x = Convert.ToChar(0x00BA).ToString(); break;
            case "Oslash": x = Convert.ToChar(0x00D8).ToString(); break;
            case "oslash": x = Convert.ToChar(0x00F8).ToString(); break;
            case "otilde": x = Convert.ToChar(0x00F5).ToString(); break;
            case "Otilde": x = Convert.ToChar(0x00D5).ToString(); break;
            case "otimes": x = Convert.ToChar(0x2297).ToString(); break;
            case "Ouml": x = Convert.ToChar(0x00D6).ToString(); break;
            case "ouml": x = Convert.ToChar(0x00F6).ToString(); break;
            case "para": x = Convert.ToChar(0x00B6).ToString(); break;
            case "part": x = Convert.ToChar(0x2202).ToString(); break;
            case "permil": x = Convert.ToChar(0x2030).ToString(); break;
            case "perp": x = Convert.ToChar(0x22A5).ToString(); break;
            case "Phi": x = Convert.ToChar(0x03A6).ToString(); break;
            case "phi": x = Convert.ToChar(0x03C6).ToString(); break;
            case "Pi": x = Convert.ToChar(0x03A0).ToString(); break;
            case "pi": x = Convert.ToChar(0x03C0).ToString(); break;
            case "piv": x = Convert.ToChar(0x03D6).ToString(); break;
            case "plusmn": x = Convert.ToChar(0x00B1).ToString(); break;
            case "pound": x = Convert.ToChar(0x00A3).ToString(); break;
            case "Prime": x = Convert.ToChar(0x2033).ToString(); break;
            case "prime": x = Convert.ToChar(0x2032).ToString(); break;
            case "prod": x = Convert.ToChar(0x220F).ToString(); break;
            case "prop": x = Convert.ToChar(0x221D).ToString(); break;
            case "psi": x = Convert.ToChar(0x03C8).ToString(); break;
            case "Psi": x = Convert.ToChar(0x03A8).ToString(); break;
            case "quot": x = Convert.ToChar(0x0022).ToString(); break;
            case "radic": x = Convert.ToChar(0x221A).ToString(); break;
            case "rang": x = Convert.ToChar(0x232A).ToString(); break;
            case "raquo": x = Convert.ToChar(0x00BB).ToString(); break;
            case "rarr": x = Convert.ToChar(0x2192).ToString(); break;
            case "rArr": x = Convert.ToChar(0x21D2).ToString(); break;
            case "rceil": x = Convert.ToChar(0x2309).ToString(); break;
            case "rdquo": x = Convert.ToChar(0x201D).ToString(); break;
            case "real": x = Convert.ToChar(0x211C).ToString(); break;
            case "reg": x = Convert.ToChar(0x00AE).ToString(); break;
            case "rfloor": x = Convert.ToChar(0x230B).ToString(); break;
            case "rho": x = Convert.ToChar(0x03C1).ToString(); break;
            case "Rho": x = Convert.ToChar(0x03A1).ToString(); break;
            case "rlm": x = Convert.ToChar(0x200F).ToString(); break;
            case "rsaquo": x = Convert.ToChar(0x203A).ToString(); break;
            case "rsquo": x = Convert.ToChar(0x2019).ToString(); break;
            case "sbquo": x = Convert.ToChar(0x201A).ToString(); break;
            case "Scaron": x = Convert.ToChar(0x0160).ToString(); break;
            case "scaron": x = Convert.ToChar(0x0161).ToString(); break;
            case "sdot": x = Convert.ToChar(0x22C5).ToString(); break;
            case "sect": x = Convert.ToChar(0x00A7).ToString(); break;
            case "shy": x = Convert.ToChar(0x00AD).ToString(); break;
            case "sigma": x = Convert.ToChar(0x03C3).ToString(); break;
            case "Sigma": x = Convert.ToChar(0x03A3).ToString(); break;
            case "sigmaf": x = Convert.ToChar(0x03C2).ToString(); break;
            case "sim": x = Convert.ToChar(0x223C).ToString(); break;
            case "spades": x = Convert.ToChar(0x2660).ToString(); break;
            case "sub": x = Convert.ToChar(0x2282).ToString(); break;
            case "sube": x = Convert.ToChar(0x2286).ToString(); break;
            case "sum": x = Convert.ToChar(0x2211).ToString(); break;
            case "sup": x = Convert.ToChar(0x2283).ToString(); break;
            case "sup1": x = Convert.ToChar(0x00B9).ToString(); break;
            case "sup2": x = Convert.ToChar(0x00B2).ToString(); break;
            case "sup3": x = Convert.ToChar(0x00B3).ToString(); break;
            case "supe": x = Convert.ToChar(0x2287).ToString(); break;
            case "szlig": x = Convert.ToChar(0x00DF).ToString(); break;
            case "Tau": x = Convert.ToChar(0x03A4).ToString(); break;
            case "tau": x = Convert.ToChar(0x03C4).ToString(); break;
            case "there4": x = Convert.ToChar(0x2234).ToString(); break;
            case "theta": x = Convert.ToChar(0x03B8).ToString(); break;
            case "Theta": x = Convert.ToChar(0x0398).ToString(); break;
            case "thetasym": x = Convert.ToChar(0x03D1).ToString(); break;
            case "thinsp": x = Convert.ToChar(0x2009).ToString(); break;
            case "thorn": x = Convert.ToChar(0x00FE).ToString(); break;
            case "THORN": x = Convert.ToChar(0x00DE).ToString(); break;
            case "tilde": x = Convert.ToChar(0x02DC).ToString(); break;
            case "times": x = Convert.ToChar(0x00D7).ToString(); break;
            case "trade": x = Convert.ToChar(0x2122).ToString(); break;
            case "Uacute": x = Convert.ToChar(0x00DA).ToString(); break;
            case "uacute": x = Convert.ToChar(0x00FA).ToString(); break;
            case "uarr": x = Convert.ToChar(0x2191).ToString(); break;
            case "uArr": x = Convert.ToChar(0x21D1).ToString(); break;
            case "Ucirc": x = Convert.ToChar(0x00DB).ToString(); break;
            case "ucirc": x = Convert.ToChar(0x00FB).ToString(); break;
            case "Ugrave": x = Convert.ToChar(0x00D9).ToString(); break;
            case "ugrave": x = Convert.ToChar(0x00F9).ToString(); break;
            case "uml": x = Convert.ToChar(0x00A8).ToString(); break;
            case "upsih": x = Convert.ToChar(0x03D2).ToString(); break;
            case "Upsilon": x = Convert.ToChar(0x03A5).ToString(); break;
            case "upsilon": x = Convert.ToChar(0x03C5).ToString(); break;
            case "Uuml": x = Convert.ToChar(0x00DC).ToString(); break;
            case "uuml": x = Convert.ToChar(0x00FC).ToString(); break;
            case "weierp": x = Convert.ToChar(0x2118).ToString(); break;
            case "Xi": x = Convert.ToChar(0x039E).ToString(); break;
            case "xi": x = Convert.ToChar(0x03BE).ToString(); break;
            case "yacute": x = Convert.ToChar(0x00FD).ToString(); break;
            case "Yacute": x = Convert.ToChar(0x00DD).ToString(); break;
            case "yen": x = Convert.ToChar(0x00A5).ToString(); break;
            case "Yuml": x = Convert.ToChar(0x0178).ToString(); break;
            case "yuml": x = Convert.ToChar(0x00FF).ToString(); break;
            case "zeta": x = Convert.ToChar(0x03B6).ToString(); break;
            case "Zeta": x = Convert.ToChar(0x0396).ToString(); break;
            case "zwj": x = Convert.ToChar(0x200D).ToString(); break;
            case "zwnj": x = Convert.ToChar(0x200C).ToString(); break;
        }
        return x;
    }  // EntityLookup()
} // class ExtendedHtmlUtility