Simple script to set cookies and check if cookie is still present.

cookies.js

var cookie = function () {
    function setCookie(name, value, expiry) {

        name = (typeof name !== 'undefined') ? name : "cookieName";
        value = (typeof value !== 'undefined') ? value : "true";
        expiry = (typeof expiry !== 'undefined') ? expiry : 1;

        var date = new Date();
        date.setTime(date.getTime() + (expiry * 1000 * 60 * 60 * 24));
        var expires = "expires=" + date.toUTCString();

        var cookieString = name + "=" + value + ";" + expires + ";path=/";

        document.cookie = cookieString;
    }

    function getCookie(name) {

        name = (typeof name !== 'undefined') ? name : "cookieName";
        var cookieName = name + "=";

        var decodedCookie = decodeURIComponent(document.cookie);
        var cookies = decodedCookie.split(';');

        for (var i = 0; i < cookies.length; i++) {
            var cookie = cookies[i];

            while (cookie.charAt(0) == ' ') {
                cookie = cookie.substring(1);
            }

            if (cookie.indexOf(cookieName) == 0) {
                return cookie;
            }
        }

        return null;
    }

    function eraseCookie(name) {
        setCookie(name, "", -1);
    }

    function isCookieSet(name) {
        return getCookie(name) !== null;
    }

    return {
        set: setCookie,
        get: getCookie,
        isSet: isCookieSet,
        erase: eraseCookie
    }

}