public string VerificationCode(string mobile)
    {
      if (IsHandset(mobile))
      {
        string code = new Random().Next(111111, 999999).ToString();
        string content = "亲，本次操作的验证码为:" + code + " 切勿泄漏此验证码信息给他人，如非本人操作，请忽略此条信息。【唐江巴巴】";
        bool ret = SendFast(mobile, content);
        if (ret)
        {
          return code;
        }
        else
        {
          return "发送失败";
        }
      }
      else
      {
        return "手机号码格式不正确";
      }
    }
    /// <summary>
    /// 验证手机号码是否合法
    /// </summary>
    /// <param name="str_handset"></param>
    /// <returns></returns>
    public bool IsHandset(string str_handset)
    {
      return System.Text.RegularExpressions.Regex.IsMatch(str_handset, @"^1[3|4|5|7|8][0-9]\d{8}$");
    }

 <?xml version="1.0" encoding="utf-8" ?><returnsms>
 <returnstatus>Success</returnstatus>
 <message>ok</message>
 <remainpoint>62095</remainpoint>
 <taskID>2779227</taskID>
 <successCounts>1</successCounts></returnsms>