function popup(page,w,h)
{
var winl = (screen.width-w)/2;
var wint = (screen.height-h)/2;
if (winl < 0) winl = 0;
if (wint < 0) wint = 0;
windowprops = "height="+h+",width="+w+",top="+ wint +",left="+
               winl +",location=no," +
               "scrollbars=no,menubars=no,toolbars=no,resizable=no,status=no";
window.open(page, "Popup", windowprops);
}