C# JavaScript unescape function

gistfile1.cs

        public static string unescape(string code)
        {
            var str = Regex.Replace(code, @"\+", "\x20");
            str = Regex.Replace(str, @"%([a-fA-F0-9][a-fA-F0-9])", new MatchEvaluator((mach) => {
                var _tmp = mach.Groups[0].Value;
                var _hexC = mach.Groups[1].Value;
                var _hexV = int.Parse(_hexC, System.Globalization.NumberStyles.HexNumber);
                return ((char)_hexV).ToString();
            }));

            return str;
        }