    public function update(){
        $login_user = $this->checkLogin();
        $item_id = I("item_id/d");  
        $item_name = I("item_name");  
        $item_description = I("item_description");  
        $item_domain = I("item_domain");  
        $password = I("password");
        $uid = $login_user['uid'] ;
        if(!$this->checkItemManage($uid , $item_id)){
            $this->sendError(10303);
            return ;
        }

        if ($item_domain) {
            
            if(!ctype_alnum($item_domain) ||  is_numeric($item_domain) ){
                //echo '个性域名只能是字母或数字的组合';exit;
                $this->sendError(10305);
                return false;
            }

            $item = D("Item")->where("item_domain = '%s' and item_id !='%s' ",array($item_domain,$item_id))->find();
            if ($item) {
                //个性域名已经存在
                $this->sendError(10304);
                return false;
            }
        }
        $save_data = array(
            "item_name" => $item_name ,
            "item_description" => $item_description ,
            "item_domain" => $item_domain ,
            "password" => $password ,
            );
        $items  = D("Item")->where("item_id = '$item_id' ")->save($save_data);
        $items = $items ? $items : array();
        $this->sendResult($items);  
    }
The web application does not, or can not, sufficiently verify whether a well-formed, valid, consistent request was intentionally provided by the user who submitted the request.