            // Make all the tabs invisible.
               for (i = 0; i < 3; i++){
                  var tab = getElementObject(selectIds[i]);
                  tab.style.display = 'none';
               }
               var selTab = getElementObject(id);
               selTab.style.display = 'block';
            } else {
             if (id == 'toc_group_by_namespace') {
               parent.indexFrame.location = indexFileNamespace;
             } else  if (id == 'toc_group_by_location') {
              