function setCookie(name, value) {
    if ((name+"="+escape(value)).length<=4000) document.cookie = name+"="+escape(value)+"; path=/";
}

function getCookie(name) {
    var prefix = name+"=";
    var cookieStartIndex = document.cookie.indexOf(prefix);
    if (cookieStartIndex == -1) return null;
    var cookieEndIndex = document.cookie.indexOf(";", cookieStartIndex+prefix.length);
    if (cookieEndIndex == -1) cookieEndIndex = document.cookie.length;
    return unescape(document.cookie.substring(cookieStartIndex + prefix.length, cookieEndIndex));
}

function deleteCookie(name) {
    if (getCookie(name)) document.cookie = name + "=; path=/; expires=Thu, 01-Jan-70 00:00:01 GMT"
}