cancel button not redirecting to separate page

Question

I have an ASP.NET form with a cancel button that is supposed to, after confirmation from the user, redirect them to another page. I'm using javascript for this. It works fine in a simple HTML page, but apparently something is interfering with it on the .aspx page. The popup message works perfectly, but clicking "Okay" does not take you to another page. I have tested the if statement and it is working correctly, the only thing it won't do is leave the current page.

My javascript:

<script type="text/javascript">
<!--
    function confirmation() {
        var answer = confirm("Are you sure you want to cancel? Any information you have entered will be discarded.")
        if (answer) {
            window.location = "index.htm";
        }
    }
-->
</script>

My button:

<asp:Button ID="btnCancel" runat="server" Text="Cancel" onClientClick="return confirmation();" CausesValidation="false" />

Answer 1

Set UseSubmitBehavior property of the button control to false:

<asp:Button UseSubmitBehavior="false" ID="btnCancel" runat="server" Text="Cancel" onClientClick="return confirmation();" CausesValidation="false" />