public statc string UrlEncode(string input)
        {
            if(input==null||"".Equals(input))return "";
            StringBuilder sb = new StringBuilder();
            byte[] byStr = System.Text.Encoding.Default.GetBytes(input);
            for(int i = 0; i < byStr.Length; i++)
            {
              sb.Append(@"%" + Convert.ToString(byStr[i],16));
            }

            return (sb.ToString());

        }