if (document.getElementById && document.createTextNode) {
	canDOM = true;
}
function collapse(id, headId) {
	if (canDOM && document.getElementById(id)) {
		elm = document.getElementById(id);
		head = document.getElementById(headId);
		if (elm.style.display=='none' || elm.style.display=='') {
			// collapse all
			for (i=0; i<elm.parentNode.childNodes.length; i++) {
				switch (elm.parentNode.childNodes[i].className) {
					case 'SitemapShow': elm.parentNode.childNodes[i].style.display='none'; break;
					case 'SitemapHide': elm.parentNode.childNodes[i].style.display='none'; break;
				}
			}
			elm.style.display='block';
			switch(head.className) {
				case 'TopicCollapsed': head.className="TopicElapsed"; break;
				case 'ArticleCollapsed': head.className="ArticleElapsed"; break;
			}
		} else {
			elm.style.display='none';		
			switch(head.className) {
				case 'TopicElapsed': head.className="TopicCollapsed"; break;
				case 'ArticleElapsed': head.className="ArticleCollapsed"; break;
			}
		}
	}
}
if (canDOM) {
	document.write('<style type="text/css">.navHide{display:none;}</style>')
}