public function generate($encrypt, $signature, $timestamp, $nonce)
{
$format = "<xml>\r\n<Encrypt><![CDATA[%s]]></Encrypt>\r\n<MsgSignature><![CDATA[%s]]></MsgSignature>\r\n<TimeStamp>%s</TimeStamp>\r\n<Nonce><![CDATA[%s]]></Nonce>\r\n</xml>";
return sprintf($format, $encrypt, $signature, $timestamp, $nonce);
}