function onMouseOver(sender, eventArgs) {
    if (eventArgs._item._imageUrl != null) {
        if (eventArgs._item._imageUrl.indexOf("-over.jpg") == -1)
            eventArgs._item.set_imageUrl(eventArgs._item._imageUrl.replace(".jpg", "-over.jpg"));
    }
}
function onMouseOut(sender, eventArgs) {
    if (eventArgs._item._imageUrl != null)
    eventArgs._item.set_imageUrl(eventArgs._item._imageUrl.replace("-over.jpg", ".jpg"));
}