function highlight(item, from, to) {
		
		var x = from;
		for (x; x <= to; x++) {
			
			var cl = document.getElementById(item + x).className;
			if (!cl.match("disabled")) document.getElementById(item + x).className = cl + ' highlight';
		}

	}

	function unlight(item, from, to) {
		
		var x = from;
		for (x; x <= to; x++) {
			
			var cl = document.getElementById(item + x).className.replace(" highlight", "");
			document.getElementById(item + x).className = cl;
		}
	}
	function show_arrows(id) {
		
		document.getElementById(id + '_left').className = 'left-arrow';
		document.getElementById(id + '_right').className = 'right-arrow';
	}	

	function hide_arrows(id) {
		
		document.getElementById(id + '_left').className = 'left';
		document.getElementById(id + '_right').className = 'right';
	}