function extractCookieValue(val)
{
    if ((endOfCookie = document.cookie.indexOf(";",val)) == -1)
    {
        endOfCookie = document.cookie.length;
    }
    return unescape(document.cookie.substring(val,endOfCookie));
}

function readCookie(cookiename)
{
    var numOfCookies = document.cookie.length;
    var nameOfCookie = cookiename+"=";
    var cookieLen = nameOfCookie.length;
    var x = 0;
    while (x <= numOfCookies)
    {
        var y = (x+cookieLen);
        if (document.cookie.substring(x,y) == nameOfCookie)
            return (extractCookieValue(y));
        x = document.cookie.indexOf(" ",x)+1;
        if (x == 0)
            break;
    }
    return (null);
}

function createCookie(name,value,expiredays)
{
    var todayDate = new Date();
    todayDate.setDate(todayDate.getDate()+expiredays);
    document.cookie = name +
                      "=" +
                      value +
                      "; expires=" +
                      todayDate.toGMTString() +
                      ";";
}