Browser current window size.
You can get the outer window size with window.outerWidth and window.outerHeight.
You can get the inner window size with window.innerWidth and window.innerHeight.
With IE you can get it with document.body.clientWidth and document.body.clientHeight.
You can get the screen window position with window.screenLeft and window.screenTop.
alert(window.outerWidth+' x '+window.outerHeight);