function getCookie(name)
{
    var start = document.cookie.indexOf(name + "=" );
    var len = start + name.length + 1;
    if((!start) && (name != document.cookie.substring( 0, name.length)))
    {
        return null;
    }
    if(start == -1) return null;
    var end = document.cookie.indexOf( ';', len );
    if (end == -1 ) end = document.cookie.length;
    return unescape(document.cookie.substring(len, end));
}

function setCookie(name, value)
{
    var today = new Date();
    var expires = null;
    today.setTime(today.getTime());
    if(expires)
    {
        expires = expires * 1000 * 60 * 60 * 24;
    }
    var expires_date = new Date(today.getTime() + (expires));
    document.cookie = 
        name + '=' + escape(value) +
        (
            ( expires ) ? ';expires='+expires_date.toGMTString() : ''
        );
}

function deleteCookie(name)
{
    if(getCookie(name))
    {
        document.cookie = name + '=' + ';expires=Thu, 01-Jan-1970 00:00:01 GMT';
    }
}