Does anyone have insight as to how to change the way the grid layouts work?

basically  instead of having two images per product, i'd like to have one image, a large one, and resize it using aspImageResize.
THis is the code on the template:
<asp:ImageButton ID="imgBtnProductImage" runat="server" CommandName="ViewProductDetail" />

Where do i find this code to modify it?{!

anyone know?