google map waypoints issue

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C#

WinMobile

Google-Maps

I'm trying to get route using google map directions service

Uri uri = new Uri("http://maps.googleapis.com/maps/api/directions/xml?origin=adrori&destination=adrdest&waypoints=adr1|adr2|....|adr8&sensor=false");
                  HttpWebRequest httpRequest = (HttpWebRequest)HttpWebRequest.Create(uri);
                  HttpWebResponse httpResponse = (HttpWebResponse)httpRequest.GetResponse();

and put the result in xml file.
After parsing the xml file and getting the path, i send onother request to google static map to display the path in a windows mobile 6 application.
Every thing works fine but i can't find a way to use more than 8 waypoints in the request.
Any help please?