Memleak...

var winMain = Titanium.UI.createWindow({
	title:'Main',
	backgroundColor:'#fff'
});
var winHolder = Titanium.UI.createWindow({
	backgroundColor: winMain.backgroundColor
});


var flexSpace = Titanium.UI.createButton({
	systemButton:Titanium.UI.iPhone.SystemButton.FLEXIBLE_SPACE
});

var btPrevious = Ti.UI.createButton({
	title: 'Previous'
});
var btNext = Ti.UI.createButton({
	title: 'Next'
});

var tbNav = Titanium.UI.createToolbar({
	items:[btPrevious, flexSpace, btNext],
	bottom: 0
});


var counter = 0
btNext.addEventListener('click', function() {
	var bg=(counter%2) ? '#ff0' : '#f00';

	var winNew = Titanium.UI.createWindow({
		title:'Current',
		backgroundColor: bg,
		url: 'win.js',
		index: ++counter + ': ' + Ti.Platform.availableMemory
	});


	var labelNext = Ti.UI.createLabel({
		text: 'Next' + winNew.index
	});

	winNew.add(labelNext);

	winHolder.add(winNew);
	winHolder.animate({
		view: winNew,
		transition: Ti.UI.iPhone.AnimationStyle.FLIP_FROM_LEFT
	});

	winThis.close();
	winThis = winNew;
	
});


var winThis = Titanium.UI.createWindow({
	title:'Current',
	backgroundColor:'#ff0',
	url: 'win.js',
	index: 0
});

var labelStart = Ti.UI.createLabel({
	text: 'Start' + counter + ': ' + Ti.Platform.availableMemory
});

winThis.add(labelStart);

winHolder.add(winThis);

winMain.add(winHolder);
winMain.add(tbNav);
winMain.open();