Assuming you're using templates:
The image:
The div/table to hide/show:
Notes:
- The image must have the expander class
- UNIQUEID must be completely unique and not used elsewhere on the page
- $expcolimage must be defined in your code based on whether its collapsed or expanded, otherwise it will not work or will show incorrect image for the collapse/expand. If you can't do that then just use collapse.gif but keep in mind that the image might become incorrect if page is refreshed.
The image:
<img src="{$theme['imgdir']}/{$expcolimage}" id="UNIQUEID_img" class="expander" alt="" title="" />
The div/table to hide/show:
<div id="UNIQUEID_e">
Notes:
- The image must have the expander class
- UNIQUEID must be completely unique and not used elsewhere on the page
- $expcolimage must be defined in your code based on whether its collapsed or expanded, otherwise it will not work or will show incorrect image for the collapse/expand. If you can't do that then just use collapse.gif but keep in mind that the image might become incorrect if page is refreshed.