// javascript to change the CSS of navigation tabs so that only one is "current"


    	function changeTab(tabId, url) {
    	
	    	// get all the <li> in <headerNav> and 
	    	// reset the class attribute
	    	var headerContainer = document.getElementById('headerNav');
	    	var navTabsCollection = headerContainer.getElementsByTagName('li');
	    	for (i=0; i<navTabsCollection.length; i++) {
	    		navTabsCollection[i].className = '';
		    }
	    		    	
	    	// change the class of the selected tab to be active    	
	    	var currTabElem = document.getElementById(tabId);
			currTabElem.setAttribute("class", "current");
			currTabElem.setAttribute("className", "current");  // IE		
			
			// change the iframe content
			frames['documents'].location.href = url;
	    }