encodage caractères html

 //encode a string in Html to avoid problems with accents
        public static string HtmlEncode(string text)
        {
            char[] chars = HttpUtility.HtmlEncode(text).ToCharArray();
            StringBuilder result = new StringBuilder(text.Length + (int)(text.Length * 0.1));

            foreach (char c in chars)
            {
                int value = Convert.ToInt32(c);
                if (value > 127)
                    result.AppendFormat("&#{0};", value);
                else
                    result.Append(c);
            }

            return result.ToString();
        }