function highlight(id,state) {
	var nav,args=highlight.arguments;
	nav = document.getElementById('nav_' + id);
	if (nav && nav.className.indexOf('current') < 0) {
		if (args.length < 2 || state.length == 0) {
			nav.className = 'current';
		}
		else {
			nav.className = state;
		}
	}			
}