let team_to_xml t =
let tname = get_team_name t in
let tgrade = get_team_grade t in
if ((tname <> "") || (tgrade > 0.)) then
[ Xml.Element ("team",[
("num", string_of_int (get_team_num t));
("name", tname);
("grade", string_of_float tgrade);
],[]) ]
else []