ASP.Net Confirm box issue

Question

In my asp.net application I have used JavaScript confirm box for user confirmation. Here is the code:

EDIT :

Answer 1

Simple solution use javascript and call OnClientClick

<script type="text/javascript">
        function confirm() {
           if (confirm('This Contract Have a Pre-Renewed,Please Delete that Contract First')) {
                return true;
            }
            else {
                return false;
            }
        }
      </script>     
 <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" OnClientClick="return  
 confirm()"/>

Answer 2

By using javascript confirm method you only decide, whether you want to continue or not - so it is ok that your Button1_Click method is called only when user clicks ok.

What you trying to do is quite different. I would suggest to get rid of ASP.NET Button control and use "common" HTML link like:

<a href="#" id="decideLink">Click me</a>

And then in javascript

document.getElementById('decideLink').onclick = function()
{
    if(proceed) {
        // do something here
    } else {
        // do something different
    }
}

To call code-behind method from javascript, check this article about calling web methods from javascript