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 writeCookie(name, value, expiresAfter) {
	var expires = "";
	if (expiresAfter) {
		var date = new Date();
		date.setTime(date.getTime() + expiresAfter);
		expires = "; expires="+date.toGMTString();
	}
	document.cookie = name + "=" + value + expires + "; path=/";
}

function deleteCookie(name) {
	writeCookie(name, '', -1);
}