<script type="text/javascript">
function openOptInConfirm(id) {
        UmbClientMgr.openModalWindow(
'/testpage.aspx?id=' + id, 'Confirm window', true, 300, 130, 80, 0, '', '');
    }
</script>

The testpage.aspx page contains two buttons, Yes and No.

What I need to know is how if the user clicks "No" I make it so that the modal window closes. And if they click "Yes" then the modal window closes and it rebinds the grid within my custom datatype to show the changes?

I did try the following code from another post but this seemed to refresh the page behind but it displayed a warning saying that data would be re-submitted and it did not close the modal window, can anyone help or suggest a better way for doing this?

System.Text.StringBuilder sb = new System.Text.StringBuilder();
sb.Append(@"<script language='javascript'>");
sb.Append(@"parent.document.getElementById('right').contentWindow.location.reload(true);top.closeModal();");
sb.Append(@"</script>");

ScriptManager.RegisterStartupScript(btnNo, this.GetType(), "JSCR", sb.ToString(), false);