登陆示例 Ext如何连接后台

登陆示例 Ext怎么连接后台
//前台显示部分

<form id="form1" runat="server">
    <div><div id="btnShow" style=" text-align:center; padding-top:300px; vertical-align:middle;"></div>
    <script type="text/javascript">
    function LoginDemo()
    {       
        //登陆窗体
        var loginPanel = new Ext.form.FormPanel
        ({
             id:"loginPanel",labelPad:0,labelWidth:40,frame:true,
             items:
             [
                 {xtype:"field",id:"UserName",fieldLabel:"用户名"},
                 {xtype:"field",id:"Password",fieldLabel:"密&nbsp;&nbsp;&nbsp;码"}
             ]        
        });
        var loginWindow;
        if(!loginWindow)
        {
            loginWindow = new Ext.Window
            ({
                 id:"loginWindow",
                 title:"登陆窗口",
                 width:200,
                 height:127,
                 resizable:false,
                 closable:false,
                 items:
                 [
                    loginPanel
                 ],
                 buttons:
                 [
                     {xtype:"button",text:"确定",handler:validatorData},
                     {xtype:"button",text:"取消",handler:function(){loginWindow.hide();}}
                 ]
            });
        }
        loginWindow.show();
        document.body.onkeydown = function(){loginWindow.show();};
        //连接数据库
        function validatorData()
        {
            var UserName = Ext.getCmp("UserName").getValue();
            var Password = Ext.getCmp("Password").getValue();
            if(Ext.util.Format.trim(UserName)==""||Ext.util.Format.trim(Password)=="")
        bsp;             {
                    Response.Write("{success:false}");
                }
            }
            else
            {
                Response.Write("{success:false}");
            }
            */
            #endregion
            Response.Write("{success:true}");
        }
    }