<?php
class LwallModel extends Model{
protected $_validate = array(

array('fs','require','请输入'),
array('fw','require','请输入'),
array('sex','require','请选择'),
array('ts','require','请输入'),
array('tw','require','请输入'),
array('words','require','请输入'),
array('code','require','请输入验证码！'),
array('code','checkcode','验证码错误',0,'callback',1),
);
protected function checkcode($code){
if($_SESSION['code']!=md5($code)){
return false;
}
else{
return true;
}


}
}
?>


这是代码，谁给我看看哪儿出问题了