single window app, check if window is closed

I've a single window app only for iOS.

I want to know if the second Window will flush memory about first window. The code works well is only and issue about memory stack.

I don't want to use other method for opening windows. I've tried also to store windows in array or Ti.App.Properties or others but I received undefined value.

example of my code:

app.js

Window = require('ui/HomeWindow');
new Window().open();

ui/HomeWindow.js

function HomeWindow() {
    var win = Ti.UI.createWindow({
        backgroundColor: 'white',
        exitOnClose: true,
        fullscreen: false,
        title: 'Home'
    });
 
    var home2 = Ti.UI.createButton({
        right:35, 
        top:25, 
        width:64, 
        height:20
    });
    home2.addEventListener('click', function(e){
 
        Window = require('ui/HomeWindow2');
        new Window().open(); 
    });
 
 
return win; 
}
module.exports = HomeWindow;