body{
 background: transparent url(background.png);
 margin:0px;
 width:100%;
 height:100%;
 overflow:hidden;
}


#container1{
 width:50%;
 height:100%;
 overflow:scroll;
 position:absolute;
}

#container2{
 left:50%;
 width:50%;
 height:100%;
 overflow:scroll;
 position:absolute;
}