Form Panel not loading in IE 6 but in IE 9 and other browsers it is opening

[saeede]

Hi ,
I have a form panel in EXTJS 3.4 ,when I run the js file by firefox or IE 9 the page show up but when I want to run the file by IE6 , the browser shows me an empty page ...
could you please help me? I need to run the page by IE6 as well as other browser like FF
here is the code:

//***********************************************

var User_Login= new Ext.FormPanel( {
renderTo: Ext.getBody(),
frame: true,
title: 'Login',
width: 250,
items: [{ xtype: 'textfield', fieldLabel: 'UserName', name: 'UserName' },{ xtype: 'textfield', fieldLabel: 'Password', name: 'Password' }, ],
buttons: [{ text: 'Save'}, { text: 'Reset', handler: function(){ User_Login().reset(); } }] });

[jorgeluislay]

viewConfig: {
forceFit: !Ext.isIE6,
emptyText: 'empty ?'
},