Is this what you're looking for?
Code:<script language="JavaScript"> sw = screen.availWidth; if (sw == 640) { x1 = 620; y1 = 460; }; if (sw == 800) { x1 = 765; y1 = 570; }; if (sw == 1024){ x1 = 800; y1 = 650; }; self.moveTo(10,10); self.resizeTo(x1,y1); </script>