function popup(object, width, height)
{
    mypopup = window.open("popup.php?object=" + object,"PopupWindow","menubar=0,scrollbars=1,resizable=1,width=" + width + ",height=" + height); 

    x = (screen.availWidth - width) / 2;
    y = (screen.avaiHeight - height) / 2

    mypopup.moveTo(x, y);
}