https://cidermics.com/js/cookie.js

1function setCookie(cookieName, value, exdays){
2    var exdate = new Date();
3    exdate.setDate(exdate.getDate() + exdays);
4    var cookieValue = escape(value) + ((exdays==null) ? "" : "; expires=" + exdate.toGMTString());
5    document.cookie = cookieName + "=" + cookieValue;
6}
7function deleteCookie(cookieName){
8    var expireDate = new Date();
9    expireDate.setDate(expireDate.getDate() - 1);
10    document.cookie = cookieName + "= " + "; expires=" + expireDate.toGMTString();
11}
12function getCookie(cookieName) {
13    cookieName = cookieName + '=';
14    var cookieData = document.cookie;
15    var start = cookieData.indexOf(cookieName);
16    var cookieValue = '';
17    if(start != -1){
18        start += cookieName.length;
19        var end = cookieData.indexOf(';', start);
20        if(end == -1)end = cookieData.length;
21        cookieValue = cookieData.substring(start, end);
22    }
23    return unescape(cookieValue);
24}