div.RadToolTip a.rtCloseButton {
    display: block;
    float: right;
    position: absolute;
    top: -1px !important;
    right: -3px !important;
    width: 26px !important;
    height: 25px !important;
    margin: 0;
    background: url(/DesktopModules/ForumModule/css/btn_CloseSml.png) top left no-repeat !important;
    z-index: 10000 !important;
}