Style Comment Form Submit Button

One of my favorite designers gave me a challenge today: replace the standard WordPress “Submit” button on comment pages with an image.

Normally this would mean changing the tags for the input button from type=submit to type=image. But WordPress has the type field hard-coded to be “submit.” (comment_form() function in wp-includes/comment-template.php).

I was about to give up when I stumbled on this article that explains how to style a type=submit button with an image.

I followed his simple example, adding one line to make the cursor change to the little finger pointer:
cursor: pointer;

See the results at