Have you ever rendered and Excel, Word, or PDF document with ASP.NET and disabled the button when the user clicked "Export To Excel" so that they would only click it once?  Then only to find out the the button is still disabled after Response.End() and you cannot enable it again?

Well the only way I found to enable the button again is with a JavaScript timer after x number of seconds. This is not the best solution if your process runs long. If you have found a better way please email me.

The code below will disable the button on an ASP.NET page after a user clicks it. Then a JavaScript will run and enable the button again after 10 seconds.

protected void Page_Load(object sender, EventArgs e)
{
    BtnPrint.Attributes.Add("onclick", "javascript:"
      + BtnPrint.ClientID + ".disabled=true;"
      + Page.ClientScript.GetPostBackEventReference(BtnPrint, null));

    //Renable the button after 10 seconds
    string Script = @"";

    Script = Script.Replace("$BTNAME", BtnPrint.ClientID);
    Page.ClientScript.RegisterStartupScript(GetType(), "script", Script);
}