Try to set the different classes in the form field and then roll over the image.
<!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"><title>Rollover</title> <link rel="stylesheet" href="3Drollovers.css" type="text/css"> </head><body> <div class=""> <a class="rollover" href="https://developer.mozilla.org/en/HTML/HTML5"> <figure class="cube"> <img src="mdnface.png" class="front" alt="MDN"> <img src="htmlface.png" class="back" alt="HTML5"> </figure> </a> </div> </body></html>