Ajax: updatepanel / timer takes focus from my dropdownlist

I use a timer and updatepanel to show clock in my page. using this codes in my aspx:

<%@ Control language="C#" Inherits="Mosi.Modules.Clock.ViewClock" CodeFile="ViewClock.ascx.cs" AutoEventWireup="true"%>
<asp:Timer ID="Tmrclk" runat="server" Interval="1000" ontick="Tmrclk_Tick">
</asp:Timer>
<asp:UpdatePanel ID="Updpanelclk" runat="server" ChildrenAsTriggers="False" 
    UpdateMode="Conditional">
<Triggers>
    <asp:AsyncPostBackTrigger ControlID="Tmrclk" EventName="Tick">
    </asp:AsyncPostBackTrigger>
</Triggers>
<ContentTemplate>
    <a开发者_JS百科sp:Label ID="lblclk" runat="server"></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>

and this code in my aspx.cs file:

    protected void Tmrclk_Tick(object sender, EventArgs e)
    {
        lblclk.Text = DateTime.Now.ToLongTimeString();
    }

I use this code as a module in dotnetnuke CMS and it works! but when in dotnetnuke I choose a control panel dropdownlist this ajax code cause the dropdownlist unfocused and close.

how can I maintain focus on this dropdownlist.

any help would be appreciated. Thanks

Why not use Javascript to show and update your time instead of ajax. I think this would be a better option for your module. Then you dont have to worry about ajax at all. Please see this link below for an example.

Display Date and Time in Javascript