var expDays = 30;
var exp = new Date();
exp.setTime(exp.getTime() + (expDays*24*60*60*1000));

function getCookieVal (offset)
{
        var endstr = document.cookie.indexOf (";", offset);
        if (endstr == -1)
        endstr = document.cookie.length;
        return unescape(document.cookie.substring(offset, endstr));
}
function GetCookie (name)
{
        var arg = name + "=";
        var alen = arg.length;
        var clen = document.cookie.length;
        var i = 0;
        while (i < clen)
                {
                        var j = i + alen;
                        if (document.cookie.substring(i, j) == arg)
                        return getCookieVal (j);
                        i = document.cookie.indexOf(" ", i) + 1;
                        if (i == 0) break;
                }
        return null;
}
function SetCookie (name, value)
{
        var argv = SetCookie.arguments;
        var argc = SetCookie.arguments.length;
        var expires = (argc > 2) ? argv[2] : null;
        var path = (argc > 3) ? argv[3] : null;
        var domain = (argc > 4) ? argv[4] : null;
        var secure = (argc > 5) ? argv[5] : false;
        document.cookie = name + "=" + escape (value) +
        ((expires == null) ? "" : ("; expires=" + expires.toGMTString())) +
        ((path == null) ? "" : ("; path=" + path)) +
        ((domain == null) ? "" : ("; domain=" + domain)) +
        ((secure == true) ? "; secure" : "");
}
function DeleteCookie (name)
{
        var exp = new Date();
        exp.setTime (exp.getTime() - 1);
        var cval = GetCookie (name);
        document.cookie = name + "=" + cval + "; expires=" + exp.toGMTString();
}