// чтение cookie
function getCookie(cookieName) {

    if (!cookieName)
        return false;
		

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

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

        if (singleCookie[0] == cookieName)
            return singleCookie[1];
    }

    return false;

}

// установка cookie
function setCookie(cookieName, cookieValue, cookieExpire) {

    if (!cookieName || !cookieValue)
        return false;

    var date = (cookieExpire ? new Date(cookieExpire) : new Date());

    document.cookie = cookieName + '=' + cookieValue +
                      '; expires=' + date.toGMTString() +
                      '; path=/';
    return true;
}

// удаление cookie
function deleteCookie(cookieName) {

    if (!cookieName)
        return false;

    var date = new Date('01/01/1970');

    document.cookie = cookieName + '=""' +
                      '; expires=' + date.toGMTString() +
                      '; path=/';   
        
    return true;
}