.hoverthumb {
    opacity:0.5;
    -moz-opacity:0.5;                           /* ff>3 */
     filter:Alpha(opacity=50, finishopacity=50); /* ie */
     height:60px;
     width:100px;
     margin-right:12px;
     margin-top:12px;
     float:left;
  }

.normalthumb{
    height:60px; 
    width:100px; 
    margin-right:12px; 
    margin-top:12px; 
    float:left;
}