Back button alloy

Hi,

I want to implement a back button in alloy.While clicking on back button previous page should be displayed.I have added code for back button as

function back()

{

Alloy.createController('index').getView().open();

}

here index page is previous page

Problem I am having index page contains paginated data and calling this function is reloading page. I tried to close current window so previous page will come into focus. But my worry is when memory become tight whether system will remove previous page so that I will end up with blank page...?

Is there any other way to do it better?

Thanks

Vivek P