function createCookie(name,value) {
	document.cookie = name + "=" + value + "; expires=01/01/2015 00:00:00; path=/";
}

function readCookie(name) {
	var nameEQ = name + "=";
	var ca = document.cookie.split(';');
	for(var i = 0; i < ca.length; i++) {
		var c = ca[i];
		while (c.charAt(0) == ' ') c = c.substring(1, c.length);
		if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length, c.length);
	}
	return null;
}

function updateCookie(name, value) {
	var list = readCookie(name);
	
	if ( list != null ) {
		if (list.indexOf(value) == -1) {
			createCookie(name,list + ',' + value);
		} else {
			return;
		}
	} else {
		createCookie(name,value)
	}
}