function PhotoGallery_ShowPopup(imgItem, NewItem) {
    var x = 0;
    var y = 0;
    var loopParent = imgItem;
    var hp = document.getElementById("PhotoGallery_HoverPopUp");

    while (loopParent.offsetParent != null)
    {  
        x += loopParent.offsetLeft;
        y += loopParent.offsetTop;
        loopParent = loopParent.offsetParent;
    }
    y += loopParent.offsetTop;

    // Set the position of hover-over popup
    hp.style["top"] = (y - 70) + "px";
    hp.style["left"] = (x + imgItem.scrollWidth - 420) + "px";
    var hiddenImage = hp.getElementsByTagName("img")[0];
    hiddenImage.src = NewItem.src;

    // Set popup to visible
    hp.style.visibility = "Visible";
}
function PhotoGallery_HidePopup() {
    var hp = document.getElementById("PhotoGallery_HoverPopUp");
    hp.style.visibility = "Hidden";
}