.vote_yes {
  width: 51px;
  height: 45px;
  background: url('http://hc2.ca/wp-content/themes/workplace/images/vote_yes.png') bottom left no-repeat; 
}

.vote_yes:hover {
  width: 51px;
  height: 45px;
  background: url('http://hc2.ca/wp-content/themes/workplace/images/vote_yes_a.png') bottom left no-repeat; 
}

.vote_no {
  width: 51px;
  height: 45px;
  background: url('http://hc2.ca/wp-content/themes/workplace/images/vote_no.png') bottom left no-repeat; 
}

.vote_no:hover {
  width: 51px;
  height: 45px;
  background: url('http://hc2.ca/wp-content/themes/workplace/images/vote_no_a.png') bottom left no-repeat; 
}