ExtJS让被遮盖的窗体显示在最前面以及解决Ext.MessageBox提示框被TabPanel覆盖的方法【转】

var formPanel = MisTab1.createAddFormPanel();
var addWin = new Ext.Window({  
    title: "添加产品类别", 
    pageX: 50,
    pageY: 50,
    width: 600,  
    height: 200,  
    plain: true, 
    resizable: false,  	    
    collapsible: true,   
    closeAction: ‘close‘,  
    closable: true,
    modal: ‘true‘,  
    buttonAlign: "center",
    bodyStyle: "padding:20px 0 0 0",
    alwaysOnTop: true,
    items: [formPanel],  
    buttons: [{  
           text: "添 加",  
           minWidth: 70,  
           handler: function() {                
           }  
       }, {  
           text: "关 闭",  
           minWidth: 70,  
           handler: function() { 
           }  
       }]    
});	
addWin.show();

var tab1GroupMgr = new Ext.WindowGroup();  
//前置窗口
tab1GroupMgr.zseed=99999;  

var addWin = new Ext.Window({  
    title: "添加产品类别", 
    pageX: 50,
    pageY: 50,
    width: 600,  
    height: 200,  
    plain: true,
    manager: tab1GroupMgr,
...

var tabPanel = new Ext.TabPanel({
	region: ‘center‘,
	activeTab:0,
	shadow: true,
	floating: true,    //去掉该配置项
	items: [{
		title: ‘欢迎页面‘
	}]
});