Button disable but not enable
<p>when i click btn control disable btn using javascript then btn click event call.
inside btn click event i write code which gives me report in excel/pdf format for that i use method 
ExportToHttpResponse(ExportFormatType.Excel, Response, true, "Report Name") which gives me exception so after this method 
or finally block when i write btn.enable=true; or use javascript then not executed.
exception is Unable to evaluate expression because the code is optimized or a native frame is on top of the call stack</p>

<p>i.e. i have to enable btn when report is generated.
as this method get executed ExportToHttpResponse() i got report
so after this method i have to enable btn control</p>

<pre><code>protected void Page_Load(object sender, EventArgs e)
{
    btnExcel.Attributes.Add("onclick", " this.disabled = true; " + ClientScript.GetPostBackEventReference(btnExcel, null) + ";");
}


protected void btnExcel_Click(object sender, EventArgs e)
{
   view_report();
    try
    {
       Rpt.ExportToHttpResponse(ExportFormatType.Excel, Response, true, " Reportname");
    }
    catch (Exception ex)
    {
        Console.WriteLine(ex.Message);
        ex = null;
    }
    finally
    {                  
       btnExcel.Enabled = true;
        ScriptManager.RegisterClientScriptBlock(Page, this.GetType(), "CallJSFunction", "myEnablefunction()", true);
    }
}
</code></pre>
