#page-body-content {
  float:left;
  width:395px;
  padding:0 18px 0 0;
  border-right:solid 4px #e7e7db;
  min-height:10em;
}
#page-additional-content {
  float:right;
  width:235px;
  padding:0 0 0 18px;
  border-left:solid 4px #e7e7db;
  position:relative;
  margin-left:-4px;
  min-height:10em;
}

#page.no-section-menu #page-body-content {
 width:510px; 
}
#page.no-section-menu #page-additional-content {
 width:310px;
}