retry/cancel popup while refreshing the page-ASP.NET C#
<p>I'm having an image button as a templatefield inside a gridview.On clicking of the image button i will retrieve a pdf document from a folder location as byte array.The method will return null if the document is not available.after that if we try to refresh the page ,it throws retry/cancel popup.</p>

<p>The grid is inside an update panel and the update panel is having postback trigger for that image button.</p>

<p>Please help me on this.</p>

<p>Thanks.</p>
