How to Disable javascript confirm box Server side Validation False button Submit Event?
<p>the user clicks the Save button in the form , 
i have to do some server side validation if server side validation false 
i want disable the javascript confirm box other wise enable javascript confirm box .
    my aspx code like this :</p>

<pre><code>   &lt;asp:Button ID="btnSubmit" Text="Submit" CssClass="blue-button" runat="server" ValidationGroup="AddM" OnClick="btnSubmit_Click" /&gt;
                                                        &lt;Ajax:ConfirmButtonExtender ID="ConfirmButtonExtender8" runat="server" TargetControlID="btnSubmit" ConfirmText="Please Confirm"&gt;
    &lt;/Ajax:ConfirmButtonExtender&gt;
</code></pre>

<p><a href="https://i.stack.imgur.com/9mDUA.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/9mDUA.png" alt="enter image description here"></a></p>