Update panel not working in shrepoint 2010

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SharePoint2010

Hi,

I tried to add update panel for avoid page refresh in visual webpart,It worked in the local environment but not working in the server when i tried to deployed.

<asp:Content ID="Main" ContentPlaceHolderID="PlaceHolderMain" runat="server">
    <asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
        <ContentTemplate>
            <fieldset style="width: 30%">
                <legend>Update Panel-1</legend>
                <asp:Label ID="lbl1" runat="server" ForeColor="green" /><br />
                <asp:Button ID="btnUpdate1" runat="server" Text="Update Both Panels" OnClick="btnUpdate1_Click" />
                <asp:Button ID="btnUpdate2" runat="server" Text="Update This Panel" OnClick="btnUpdate2_Click" />
            </fieldset>
        </ContentTemplate>
    </asp:UpdatePanel>
    <asp:UpdatePanel ID="UpdatePanel2" runat="server" UpdateMode="Conditional">
        <ContentTemplate>
            <fieldset style="width: 30%">
                <legend>Update Panel-2</legend>
                <asp:Label ID="lbl2" runat="server" ForeColor="red" />
            </fieldset>
        </ContentTemplate>
        <Triggers>
            <asp:AsyncPostBackTrigger ControlID="btnUpdate1" EventName="Click" />
        </Triggers>
    </asp:UpdatePanel>
</asp:Content>