function setCookie (name, value, expires) 
{
    if (!expires) {expires = new Date();}
    document.cookie = name + "=" + escape (value) + "; expires=" + expires.toGMTString() + "; path=/"; 
}

function getCookie (name) 
{
    var dcookie = document.cookie; 
    var cname = name + "=";
    var clen = dcookie.length;
    var cbegin = 0;
    while (cbegin < clen) 
    {
        var vbegin = cbegin + cname.length;
        if (dcookie.substring(cbegin, vbegin) == cname) 
        { 
            var vend = dcookie.indexOf (";", vbegin);
                if (vend == -1) vend = clen;
            return unescape(dcookie.substring(vbegin, vend));
        }
        cbegin = dcookie.indexOf(" ", cbegin) + 1;
        if (cbegin == 0) break;
    }
    return null;
}

function delCookie (name) 
{
    var expireNow = new Date();
    document.cookie = name + "=" +
    "; expires=Thu, 01-Jan-70 00:00:01 GMT" +  "; path=/";
}