#left{
float:left;
padding:0 20px 0 0;
margin:0 20px 0 0;
background:url(../images/left_shadow.png) right 50% no-repeat;

}
#right{
float:right;
padding:0 0 0 20px;
margin:0 0 0 20px;
background:url(../images/right_shadow.png) left 50% no-repeat;

}