Easiest way to open a download window without navigating away from the page

Question

What is the best cross browser way to open a download dialog (let's assume we can set content-disposion:attachment in the headers) without navigating away from the current page, or opening popups, which doesn't work well in Internet Explorer(IE) 6.

Answer 1

This javascript is nice that it doesn't open a new window or tab.

window.location.assign(url);