//we don't support 640x480 if ( screen.height < 500 ) { alert ("Sorry, your screen resolution is below 800x600. Please increase your screen resolution and login again."); } else { // align the new window to top left corner if the resolution is 800x600. if ( screen.height == 600 ) { wleft = 0; wtop = 0; } else // align to center of screen { wleft = screen.width/2 - width/2; wtop = screen.height/2 - height/2; }