DBGridEh Access

procedure TfrmMain.spbDBMGRClick(Sender: TObject);
begin
  with TOpenDialog.Create(Self) do
    try
      if edDBMGR.Text>'' then
         InitialDir := edDBMGR.Text
      else
         InitialDir := ExtractFilePath(Application.ExeName);
      Filter := 'Access files|*.mdb';
      Options := [ofReadOnly];
      if Execute then
        begin
         TargetFile := FileName;
         edDBMGR.Text := TargetFile;
         SaveSettings;
         ObserveDataBase;
        end;
    finally
      Free;
    end;
end;

begin
  if dlgOpen1.Execute then
  begin
Form1.qry1.Close;
form1.qry1.connectionstring:='Provider=Microsoft.Jet.OLEDB.4.0;Data Source='+ dlgOpen1.FileName +';Persist Security Info=False';
Form1.qry1.Active:=True;
if form1.qry1.Active then
begin
Form1.qry1.First;
Form1.mtblh1.Active:=True;
end;