php短信接口

$requestUrl ="http://sms.webchinese.cn/web_api/?"; //接口地址
    $par = array(
        'Uid' => "yijiabao",
        'Key' => "c4321d062b3688bc2a13",
        'smsMob' => $phone,
        'smsText' => iconv("UTF-8","GBK",$code),
    );
    $url = $requestUrl . http_build_query($par);
    $res = do_post($url, array());
    if($res>0){
      return array('status' => 0, "", 'msg' => "SUCESS");  
    }else{
            switch ($res) {
            case -1:
                $msg = "没有该用户账户";
                break;
            case -2:
                $msg = "密钥不正确";
                break;
            case -3:
                $msg = "短信数量不足";
                break;
            case -11:
                $msg = "该用户被禁用";
                break;
            case -4:
                $msg = "手机号格式不正确";
                break;
            case -41:
                $msg = "手机号码为空";
                break;
            case -42:
                $msg = "短信内容为空";
                break;
            case -51:
                $msg = "短信签名格式不正确";
                break;
            default:
                $msg = "未知错误";
                break;
        }
    }
    return array('status' => 1, "", 'msg' => $msg);