function Center(Popup) {

    var divPopup = $(Popup);

    var windowHeight = $(window).height();
    var popupHeight = divPopup.height();

    var top = Math.round((windowHeight - popupHeight) / 2);
    if (top < 5) {
        top = 5;
    }

    top = top - divPopup.offsetParent().offset().top;
    divPopup.css("top", top + "px");
}