请高手帮我看看，该怎么改

小弟新手，想做一个数据库查询，出错了，
procedure TForm1.BitBtn1Click(Sender: TObject);VAR i,j:INTEGER;
begin
  FORM3.SimpleDataSet1.Close;
  FORM3.SimpleDataSet1.DataSet.CommandText:='SELECT * FROM wz';
  FORM3.SimpleDataSet1.Open;
  j:=FORM3.SimpleDataSet1.RecordCount;
  if i>0 then
  begin
    FORM3.StringGrid1.RowCount:=2;
    FORM3.StringGrid1.Rows[1].Clear;
    FORM3.StringGrid1.RowCount:=j+1;
    for i:=1 to j do
    begin
      FORM3.StringGrid1.Cells[0,i]:=trim(FORM3.SimpleDataSet1.FieldbyName('档案编号').AsString);
      FORM3.StringGrid1.Cells[1,i]:=trim(FORM3.SimpleDataSet1.FieldbyName('操作员').AsString);
      FORM3.StringGrid1.Cells[2,i]:=trim(FORM3.SimpleDataSet1.FieldbyName('立案').AsString);
      FORM3.StringGrid1.Cells[3,i]:=trim(FORM3.SimpleDataSet1.FieldbyName('调查').AsString);
      FORM3.StringGrid1.Cells[4,i]:=trim(FORM3.SimpleDataSet1.FieldbyName('定性').AsString);
      FORM3.StringGrid1.Cells[5,i]:=trim(FORM3.SimpleDataSet1.FieldbyName('处置').AsString);
      FORM3.StringGrid1.Cells[6,i]:=trim(FORM3.SimpleDataSet1.FieldbyName('结案').AsString);
      FORM3.StringGrid1.Cells[7,i]:=trim(FORM3.SimpleDataSet1.FieldbyName('归档').AsString);
      FORM3.SimpleDataSet1.Next;
    end;
  end;
end;出错[Warning] Unit1.pas(126): Variable 'i' might not have been initialized要怎么改