记在thinkPHP中一个创建模型的小错误

class ManagerModel {
    //put your code here
    function checkDenglu($name,$pwd){
        $info=$this->getByMg_name($name);
        show($info);
    }
}

class ManagerModel extends Model{
    //put your code here
    function checkDenglu($name,$pwd){
        $info=$this->getByMg_name($name);
        show($info);
    }
}