I'm trying to add a menu but I've tried many things and it still doesn't work. I'm new to the Air part of EXTJS so please help.

When I try to launch the app the window doesn't show. If I take the appMenu.add() function out it'll open but there will be no menu shown, of course.I got an error on line 51 which is the line at the bottom to start var xwin.

Code:
Ext.air.Window = Ext.extend(Ext.Window,{
    maximizable: true,
//	maximized: true,
    minimizable: true,
    resizable: false,
    constrain: true,
    initComponent : function(){
        this.nativeWindow = new Ext.air.NativeWindow({
            id: 'mainWindow',
            instance: window.nativeWindow,
            width: this.width+10,
            height: this.height+10
        }).show();
        Ext.air.Window.superclass.initComponent.call(this);
    },
    maximize : function(){
        window.nativeWindow.maximize();
        Ext.air.Window.superclass.maximize.call(this);
    },
    restore : function(){
        window.nativeWindow.restore();
        Ext.air.Window.superclass.restore.call(this);
    },
    close : function(){
        Ext.air.Window.superclass.close.call(this);
        window.nativeWindow.close();
    },
    minimize : function(){
        window.nativeWindow.minimize();
    },
    initDraggable : function(){        
        this.dd = new Ext.air.Window.DD(this);  
    }
});
Ext.air.Window.DD = Ext.extend(Ext.Window.DD,{
    moveOnly:true,
    headerOffsets:[100, 25],
    startDrag: function(){
        window.nativeWindow.startMove();
        Ext.air.Window.DD.superclass.startDrag.call(this);
    },
    onDrag : function(e){
       //This seems to stop scroll bars from appearing
    }
});
Ext.onReady(function(){
	var appMenu = Ext.air.SystemMenu;	
	appMenu.add("File", [
		{text: "New Something"}
	]);
    var xwin = new Ext.air.Window({
        title: 'title here',
		html: "body here",
        width: 800,
        height: 600
    });
    xwin.show();
});