province:=treeview1.Selected.parent.Text;
          area:=treeview1.Selected.Text;
          adoquery1.SQL.Clear;
          adoquery1.SQL.Add('select * from stuinfo where (省份=:a)and(地区=:b)');
          adoquery1.Parameters.parambyname('a').value:=province;
          adoquery1.Parameters.parambyname('b').value:=area;
          adoquery1.Open;