If you want to replace the button element:
$('the-button').bind('click', function () { $(this).replaceWith('<img src="/wherever.jpg"/>'); });
If you want to change the background image of the button:
$('the-button').bind('click', function () { $(this).css('backgroundImage', 'url(\'/wherever.jpg\')'); });
If you want to change the background image of the image (: S):
$('the-button').bind('click', function () { $(this).replaceWith('<img src="/wherever.jpg" style="background-image:url(\'/somewhere-else.jpg\');"/>'); });
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