We had another one of those infamous screen resolution debates at work today, which reminded me that I once made a little javascript that sets the browser window to specific sizes, and reports the current available content area. I copy-pasted this page together a few years back and was quite surprised to find it still works, even in IE7.

Javascript browser resize and size detection

Please keep in mind that setting your browser to a say 800*600 on a 1024*768 (or better) screen will not give an accurate indication of the available space if you’re designing for users with an actual 800*600 screen. Those users will probably have maximized their browser windows. At it’s maximized setting, the margins are slightly different and the windows taskbar comes into play.