function getCookie(name, opt_defValue)
{
    var dc = document.cookie;
    var prefix = name + "=";
    var begin = dc.indexOf("; " + prefix);
    if (begin == -1)
    {
        begin = dc.indexOf(prefix);
        if (begin != 0) return opt_defValue;
    }
    else
    {
        begin += 2;
    }
    var end = document.cookie.indexOf(";", begin);
    if (end == -1)
    {
        end = dc.length;
    }
    return unescape(dc.substring(begin + prefix.length, end));
}
function setCookie(name, value, opt_expires, opt_path, opt_domain, opt_secure)
{
    document.cookie= name + "=" + escape(value) +
        ((opt_expires) ? "; expires=" + opt_expires.toGMTString() : "") +
        ((opt_path) ? "; path=" + opt_path : "") +
        ((opt_domain) ? "; domain=" + opt_domain : "") +
        ((opt_secure) ? "; secure" : "");
}
function deleteCookie(name, path, domain)
{
    var exp = new Date();
    exp.setTime(exp.getTime() - 30*24*60*60*1000);
    if (getCookie(name))
    {
        document.cookie = name + "=" +
            ((path) ? "; path=" + path : "") +
            ((domain) ? "; domain=" + domain : "") +
            "; "+exp.toGMTString();
    }
}