// cookie
function getCookie(name) {
	var dc = document.cookie;
	var prefix = name + "=";
	var begin = dc.indexOf(prefix);
	if (begin == -1)
	return null;
	var end = document.cookie.indexOf(";", begin);
	if (end == -1)
	end = dc.length;
	return unescape(dc.substring(begin + prefix.length, end));
}