function open_popup(doc,width,height) {

        left = ((screen.width - width) / 2) - 13;
        popup_win = window.open(doc,"PopUp","width="+width+",height="+height+",left="+left+",top=100,location=0,menubar=0,resizable=0,scrollbars=1,status=0,titlebar=0,toolbar=0");
        popup_win.focus();
}