function popup(s,w,h) {
                var width = screen.width;
                var height = screen.height;
                width = Math.floor((width / 2) - (w / 2));
                height = Math.floor((height / 2) - (h / 2));
                window.open(s,'','scrollbars=0,status=0,toolbar=0,location=0,menubar=0,top='+height+',left='+width+',width='+w+',height='+h+',resizeable=0')
        }