HtmlEncode src

 /// <summary>
        /// HTML-encodes a string and returns the encoded string.
        /// </summary>
        /// <param name="text">The text string to encode. </param>
        /// <returns>The HTML-encoded text.</returns>
        public static string HtmlEncode(string text) {
            if(text == null)
                return null;

            StringBuilder sb = new StringBuilder(text.Length);

            int len = text.Length;
            for(int i = 0;i < len;i++) {
                switch(text[i]) {

                    case '<':
                        sb.Append("&lt;");
                        break;
                    case '>':
                        sb.Append("&gt;");
                        break;
                    case '"':
                        sb.Append("&quot;");
                        break;
                    case '&':
                        sb.Append("&amp;");
                        break;
                    default:
                        if(text[i] > 159) {
                            // decimal numeric entity
                            sb.Append("&#");
                            sb.Append(((int)text[i]).ToString(CultureInfo.InvariantCulture));
                            sb.Append(";");
                        }
                        else
                            sb.Append(text[i]);
                        break;
                }
            }
            return sb.ToString();
        }