Catdog
http://stackoverflow.com/questions/27192353/css-how-to-do-image-change-on-rollover
by chepe263
HTML
<a href="#" id="cambio">
<input type="button" id="dog" value="Perro" />
<input type="button" id="cat" value="Gato" />
</a>
CSS
#dog{
display: none;
}
#cambio:hover > #cat{
display: none;
}
#cambio:hover > #dog{
display:block;
}