rem: { document.getElementById( this.contentFrame ).setAttribute( "tag", newTag ); } 
add: document.getElementById( this.contentFrame ).removeAttribute( "tag" ); else document.getElementById( this.contentFrame ).setAttribute( "tag", newTag ); 
context:       switchPage:        function ()          {            var prefPanelTree = document.getElementById( "prefsTree" );            var selectedItem = prefPanelTree.selectedItems[0];            var oldURL = document.getElementById( this.contentFrame ).getAttribute("tag");            if( !oldURL )              {                oldURL = document.getElementById( this.contentFrame ).getAttribute("src");              }            this.wsm.savePageData( oldURL );      // save data from the current page.             var newURL = selectedItem.firstChild.firstChild.getAttribute("url");            var newTag = selectedItem.firstChild.firstChild.getAttribute("tag");            if( newURL != oldURL )              {                document.getElementById( this.contentFrame ).setAttribute( "src", newURL );                if( !newTag )                  {                    document.getElementById( this.contentFrame ).setAttribute( "tag", newTag );                  }              }          },
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/f1cb8ef1912d289cfe094c03db343d4ea3f0d833/nsPrefWindow.js/buggy/xpfe/components/prefwindow/resources/content/nsPrefWindow.js