Adding an action bar for iOS in Titanium

I am creating a cross platform app with Titanium. The thing is that I call a js with the following code:

bot_import.addEventListener('click', function(e) {
    var ModImport = require('ModImport');
    var importPage = new ModImport();
    importPage.open();
});

The thing is that in ModImport.js I caot use the following statement in the end: open.importsWin();

Instead of that, I must use:

retu importsWin;

But, in order to make an action bar for iOS I had to use this code:

var wini = Titanium.UI.iOS.createNavigationWindow({
    window : importsWin
});

The problem is that if I do a:

retu wini;

I got a msg in the app: "Undefinied is not a function", however, if I use:

retu importsWin;

I do not have any issue but the action bar in iOS does not show up.

I hope you understand my problem and I would appreciate if someone can help me.

Thanks in advance.