function popUp(URL) {
        w = 850;
        h = 500;
        leftPosition = (screen.width) ? (screen.width-w)/2 : 0;
        topPosition = (screen.height) ? (screen.height-h)/2 : 0;
        day = new Date();
        id = day.getTime();
        eval("page" + id + " = window.open(URL, '" + id + "', 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,width="+w+",height="+h+",left="+leftPosition+",top="+topPosition+"');");
        }