/**
 * 32位UUID
 * @return string uuid
 */
function util_uuid(){

	if(function_exists('com_create_guid')){
		return str_replace('-', '', substr(com_create_guid(), 1, 36));
	}else{
		mt_srand((double)microtime()*10000);
		$uuid = strtoupper(md5(uniqid(rand(), true)));
		return $uuid;
	}
}