Why not use an iframe that covers the entire page?
var body = document.getElementById("body");
body.innerHtml = '<iframe height="100%" width="100%" src="page_you_want_to_show"></iframe>'
I mean, it could work.. probably not the best decision, but still..
Using replace() is better for redirect, because it does not keep the originating page in the session history, meaning the user won’t get stuck in a never-ending back-button fiasco. More... http://net-informations.com/q/mis/redirect.html