Could you elaborate on how to do this?

I see that this is the template to edit: include_post_display.html

Right at:

<%body_font%>
<a href="gforum.cgi?do=post_attachment;postatt_id=<%postatt_id%>;<%hidden_query%>">
<img src="<%GForum::Attachment::icon($postatt_content, $postatt_filename)%>" border=0>
<%postatt_filename%>
</a>
(<%GForum::Attachment::friendly_size($postatt_size)%>)
<%/body_font%>


But how do I do an <%if%> statement that checks postatt_filename to see if it contains ".gif" or ".jpg" at the end?

Thanks for your help!

Stephen