.user a img {
  opacity: 0.6;
  -moz-transition-property: opacity;
  -moz-transition-duration: 0.6s;
  -webkit-transition-property: opacity;
  -webkit-transition-duration: 0.6s;
  -o-transition-property: opacity;
  -o-transition-duration: 0.6s;
  transition-property: opacity;
  transition-duration: 0.6s;
  filter:alpha(opacity=60);
}

.user a img:hover {
  opacity: 1.0;
  filter:alpha(opacity=100);
}