Session.SessionId persistence in requests to ashx
===

when i make a webrequest call to a service, why does it always generates a new sessionid?

This is how i call from sitea.com

    WebClient fs = new WebClient();
                var data = fs.DownloadData("http://siteb.com/serice.ashx");
                var tostring = System.Text.Encoding.ASCII.GetString(data);
                return tostring;

This is the service code at siteb.com

    [WebMethod(EnableSession = true)]
        private string Read(HttpContext context)
        {
            var value = context.Session.SessionId;
            if (value !=null) return value.ToString();
                return "false";
        }

value is always different for every request. How can i persist this?