a.imageLink { 
   display:block; 
   background:url(http://www.cs.mcgill.ca/~jbedar8/ass5/helpbutton.png) right no-repeat; 
   float: right;
   width: 41px;
   height: 43px; 
} 

a.imageLink:hover { 
   background:url(http://www.cs.mcgill.ca/~jbedar8/ass5/backgroundHover3.png) right no-repeat;
   width: 840 px;
   height: 670px;
   right:0px;
   position:absolute;
   z-index:1
} 

a.imageLink span { 
   visibility:hidden; 
}

body.back{
   background:url(http://www.cs.mcgill.ca/~jbedar8/ass5/loginimage.png) no-repeat;
}

.center {
   left:30px;
   right: 30px;
   text-align:center;
   position:absolute
}