Hi all!
I have a gridview with a templatefield and an imagebutton

<asp:TemplateField>
<ItemTemplate>
<asp:ImageButton ID="Riepilogo" runat="server"
CommandArgument="<%#((GridViewRow)Container).RowIndex%>"
ImageUrl="~/img/search.png"
CommandName="riepilogo" ToolTip="Riepilogo attivit&#224; impianto"
onClick="prova" OnClientClick="src='img/blue_loader.gif'; Visible='True'"/>
</ItemTemplate>
</asp:TemplateField>

When i click that imagebutton, the onclientclick event changes the standard
image to a "waiting" animated gif.

The code for CommandName is something like that:
...
Response.ClearHeaders();
Response.Clear();
Response.AddHeader("Content-Disposition", "attachment;
filename=output.pdf");
Response.ContentType = myStuff.getAppSetting("ContentTypePDF");
Response.Flush();
Response.BinaryWrite(pdf);
Response.End();
...

This generates a PDF files that pops up for the download.

Now i have to change the image back to normal (not waiting). How do i
accomplish this?

Thank you in advance.