How to hide ajax modal popup extender when clicking browser's back button?
<p>I have shown one confirmation message using ajax modal pop up extender during button click in server side in asp.net. After showing that confirmation message, when i click browser's back button, the same pop up confirmation message coming again. How to hide that pop up message when i click browser's back button?</p>

<p>My Code is </p>

<pre><code>    &lt;asp:Button ID="btnShowPopup" runat="server" Style="display: none" /&gt;
    &lt;asp:Panel runat="server" ID="pnlInterfaceDetails" Style="display: none;"&gt;
                &lt;asp:Label ID="Label1" runat="server" Text="Confirmation Message" Font-Bold="true"
                    Font-Size="10pt" Style="color: White; font-family: Sans-Serif Verdana Arial"&gt;&lt;/asp:Label&gt;
                &lt;table&gt;
                    &lt;tr style="height: 35px"&gt;
                        &lt;td colspan="2"&gt;
                            &lt;b&gt;&lt;span style="color: Black;"&gt;Data Saved Successfully.&lt;/span&gt;&lt;/b&gt;
                        &lt;/td&gt;
                    &lt;/tr&gt;
                    &lt;tr style="height: 35px"&gt;
                        &lt;td align="center" colspan="2"&gt;
                            &lt;asp:Button runat="server" ID="btnConfirmClose" Text="Close" ToolTip="Close" Width="65px"
                                OnClick="btnConfirmClose_Click" CssClass="buttonOrangebg" /&gt;
                        &lt;/td&gt;
                    &lt;/tr&gt;
                &lt;/table&gt;
    &lt;/asp:Panel&gt;
    &lt;asp:ModalPopupExtender runat="server" ID="mpeInterfaceDetails" TargetControlID="btnShowPopup"
        BackgroundCssClass="modalBackground" PopupControlID="pnlInterfaceDetails" /&gt;
&lt;/div&gt;
</code></pre>
