How can i change the image of an image button clientside, on click.

I have tried this:

```
function changetoDownload(theId) {
   $(theId.id).delay(2000)
   .queue(function (next) { $(theId).attr("ImageURL", "Images/Apps/free.png"); next(); });
}

<asp:ImageButton ID="ImageButton1" OnClick="Button7_Click" OnClientClick="changetoDownload(this.id);" ImageUrl="Images/download.gif" runat="server" />

```