I want to replace the default grey submit button with an image. I can do this by adding a background image in the style sheet for .sidebar .w2linput.submit, however the cursor doesn't change when you hover over it (so it doesn't look like you can click it).
By editing the salesforce.php, I tried replacing instances of input type="submit" with input type="image". This largely failed. The image showed up properly and the cursor changed in Chrome (though it came with a border I couldn't get rid of) but the image just didn't show up in Firefox or IE.