Cookies Helper in Javascript

cookiesHelper.js

function CookiesHelper() {}

// usage
// CookiesHelper.createCookie("myCookieUniqueName", value, 30);
// CookiesHelper.createCookie("myJsonCookieUniqueName", json, 30);
CookiesHelper.createCookie = function(name, value, days) {
    if (days) {
        var date = new Date();
        date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
        var expires = "; expires=" + date.toGMTString();
    }

    else var expires = "";
    document.cookie = name + "=" + value + expires + "; path=/";
}

// usage
// var value = CookiesHelper.readCookie("myCookieUniqueName");
// var json = JSON.parse(CookiesHelper.readCookie("myJsonCookieUniqueName");
CookiesHelper.readCookie = function(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;
}

CookiesHelper.eraseCookie = function(name) {
    createCookie(name, "", -1);
}

cookiesHelper.old.js

// usage
// createCookie("myCookieUniqueName", value, 30);
// createCookie("myJsonCookieUniqueName", json, 30);
function createCookie(name, value, days) {
    if (days) {
        var date = new Date();
        date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
        var expires = "; expires=" + date.toGMTString();
    }

    else var expires = "";
    document.cookie = name + "=" + value + expires + "; path=/";
}

// usage
// var value = readCookie("myCookieUniqueName");
// var json = JSON.parse(readCookie("myJsonCookieUniqueName");
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 eraseCookie(name) {
    createCookie(name, "", -1);
}

If anyone stumbles across this, toGMTString is now deprecated, toUTCString is recommended instead.