function showPanel() {
        $find('modal').show();
        setTimeout("hidePanel()",2000);
    }
       function hidePanel() {
       $find('modal').hide();

    }
    </script>
</head>

<cc1:ModalPopupExtender ID="ModalPopupExtender1" runat="server" TargetControlID="SepeteEkle" PopupControlID="bilgi" DropShadow="true" BehaviorID="modal">

$find('behaviorID')

function showPanel()
{
    $find('behaviorID').show();
    setTimeout("hidePanel()",2000);
}

function hidePanel()
{
    $find('behaviorID').hide();
}