javascript confirmation dialog box
<p>I have a page with a button and when it is clicked, it will execute a long time task asynchronously. I tried to implement validation on that button using javascript and a confirmation dialog box will pop up when it is clicked. But when i clicked on 'Cancel' in the confirmation dialog box, the long time task still will be executed instead of returning false.</p>

<p>Any idea guys? Any help is appreciated!</p>

<p><strong>Code-Behind:</strong></p>

<pre><code>btnPrint.Attributes.Add("onclick", "javascript:submittingID='btnAdd';return validation();")

Public Sub LongTimeTask()
   .......
End Sub
</code></pre>

<p><strong>Javascript:</strong></p>

<pre><code>function validation() {
    ....
    confirmPrint()
}

function confirmPrint() {
        if (confirm("Are you sure you want to print? This process may take up to few minutes.") == true)
            return true;
        else
            return false;
}
</code></pre>
