xloadtree 在ext Viewport 里面加载不出来？

[sw245711601]

  //选项卡面板
    var tabs = new Ext.TabPanel({
        region:'center',
        resizeTabs:true, // turn on tab resizing
        minTabWidth: 115,
        tabWidth:135,
        enableTabScroll:true,
        margins : '5 5 5 0',
		layoutOnCardChange:true,
        defaults: {autoScroll:true},
		activeItem : 0,
		items:grid
    });
    
    /***************主面板****************/
	new Ext.Viewport({
		layout:'border',
		renderTo:Ext.getBody(),
	    items: [{
	        region: 'west',
	        title :'网点区域列表',
	        width:800,
	        collapsible:true,
			autoLoad: '/Util/Tree.aspx'
	    },
	    tabs
	    ]
	});

tree.aspx

 webFXTreeConfig.rootIcon        = "/Images/xp/totalicon.png";
  webFXTreeConfig.openRootIcon    = "/Images/xp/allmanagemenu.png";
  webFXTreeConfig.folderIcon        ="/Images/xp/totalicon.png";
  webFXTreeConfig.openFolderIcon    ="/Images/xp/allmanagemenu.png";
  webFXTreeConfig.fileIcon        = "/Images/xp/file.png";
  webFXTreeConfig.lMinusIcon        ="/Images/xp/Lminus.png";
  webFXTreeConfig.lPlusIcon        ="/Images/xp/Lplus.png";
  webFXTreeConfig.tMinusIcon        ="/Images/xp/Tminus.png";
  webFXTreeConfig.tPlusIcon        ="/Images/xp/Tplus.png";
  webFXTreeConfig.iIcon            ="/Images/xp/I.png";
  webFXTreeConfig.lIcon            ="/Images/xp/L.png";
  webFXTreeConfig.tIcon            ="/Images/xp/T.png";

 var tree = new WebFXTree("订单管理");
tree.add(new WebFXTreeItem("Tree Item 1"));
tree.add(new WebFXLoadTreeItem("区域", "/Util/Area.aspx"));
tree.add(new WebFXTreeItem("Tree Item 4"));
tree.write(); 

在页面中不显示出来。为什么？

[sw245711601]

大神啊 救救我啊