My problem is when page load work it shows a blank balloon , it happen each time the page load run
How i can hide it in page load and show it only when target Control click.
my HTML is
<ajaxToolkit:TabContainer ID="TabContainer1" runat="server" ActiveTabIndex="0" CssClass="MyTabStyle">
<ajaxToolkit:TabPanel ID="TabPanel1" runat="server">
<ContentTemplate>
<asp:TextBox ID="txt_SMSBody" runat="server" CssClass="txt_New" TextMode="MultiLine" Width="391px" Height="200px" Style="margin: 0 auto; font-size: medium; padding: 10px;"></asp:TextBox>
<ajaxToolkit:BalloonPopupExtender ID="txt_SMSBody_BalloonPopupExtender" BehaviorID="Ba" runat="server" Enabled="true" TargetControlID="txt_SMSBody" BalloonPopupControlID="pnl_SMSBody" Position="TopRight" BalloonStyle="Custom" CustomCssUrl="css/StyleSheet.css"
CustomClassName="custom-popup">
</ajaxToolkit:BalloonPopupExtender>
<asp:Panel ID="pnl_SMSBody" runat="server" Style="font-family: 'GE_TwoLight'; padding: 15px;">Hint</asp:Panel>
</ajaxToolkit:TabPanel>
</ajaxToolkit:TabContainer>