2.后台校验：

* */
  public function check_login(){
    $password=I('param.password');
    $username=I('param.username');
    $data["name"]=$username;
    $user=M('systemuser');
    $list=$user->where($data)->find();
    $return=0;
    if($list!=""){
      if($list['password']==md5($password) && $list['status'] == 1){
        //登录时间和登录IP
        $public = new PublicController();
        $lastlogonip=$public->ip_address();
              
        $time=$time=date("Y-m-d H:i:s", time());
        $where=array('id'=>$list['id']);
        
        $user->where($where)->save(array('lastlogonip'=>$lastlogonip,'lastlogontime'=>$time));
        $this->login($list);
        $return=1;//登录成功
      }
    }else{
      $return=2;//登录失败
    }
    $this->ajaxReturn($return);
  }