Как открывать через OpenDialog файлы mdb?

procedure TForm1.openClick(Sender: TObject);
var
r: integer;
begin
 if opendialog1.execute then
 begin
   DBgrid1.columns.loadfromfile (opendialog1.FileName);
 end;
end;

DBgrid1.columns.loadfromfile (opendialog1.FileName);

[size="1"][color="grey"][I]Добавлено через 4 часа 48 минут[/I][/color][/size]
unit MainForm;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, DB, ADODB, Grids, DBGrids, StdCtrls, FindForm, findeform2ver,
  ExtCtrls, findfordate, DBCtrls, DBClient, Menus;
 
type
  TForm1 = class(TForm)
    DBGrid1: TDBGrid;
    ADOConnection1: TADOConnection;
    ADODataSet1: TADODataSet;
    DataSource1: TDataSource;
    Button2: TButton;
    Image1: TImage;
    Button3: TButton;
    CheckBox1: TCheckBox;
    CheckBox2: TCheckBox;
    CheckBox3: TCheckBox;
    DBNavigator1: TDBNavigator;
    MainMenu1: TMainMenu;
    N1: TMenuItem;
    open: TMenuItem;
    new: TMenuItem;
    N5: TMenuItem;
    N6: TMenuItem;
    save: TMenuItem;
    N2: TMenuItem;
    N3: TMenuItem;
    OpenDialog1: TOpenDialog;
    ADOTable1: TADOTable;
    ADOTable1Name: TWideStringField;
    ADOTable1Number: TWideStringField;
    ADOTable1passport: TWideStringField;
    ADOTable1coste: TIntegerField;
    ADOTable1data: TDateTimeField;
    procedure FormActivate(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure Button2Click(Sender: TObject);
        procedure Button3Click(Sender: TObject);
    procedure CheckBox1Click(Sender: TObject);
    procedure CheckBox2Click(Sender: TObject);
    procedure CheckBox3Click(Sender: TObject);
    procedure newClick(Sender: TObject);
    procedure openClick(Sender: TObject);
 
 
  private
    { Private declarations }
 
  public
    { Public declarations }
 
  end;
 
var
  Form1: TForm1;
 
   implementation
 
{$R *.dfm}
 
procedure TForm1.Button2Click(Sender: TObject);
begin
adodataset1.Filtered := false;
end;
 
procedure TForm1.Button3Click(Sender: TObject);
 
begin
 
   begin
 
    if checkbox3.Checked then
         begin
 
        form4.ShowModal;
      if form4.ModalResult = mrOK then
        with ADODataSet1 do
          begin
            adodataset1.Close;
            CommandText := 'select * from contacts WHERE data = :X';
            Parameters.ParamByName('X') .Value := form4.DateTimePicker1.Date;
            adodataset1.Open;
          end;
         end;
 
 
 
 
      end;
       begin
          begin
 if checkbox1.checked then Form3.ShowModal;
          end;
          begin
            if checkbox2.Checked then Form3.ShowModal;
 
          end;
 if form3.ModalResult = mrOK then
   begin
    if checkbox1.Checked then begin
       AdoDataset1.Filtered := false;
   Adodataset1.Filter := 'name like ''%' + form3.Edit1.text + '%''';
   AdoDataset1.Filtered := True
      end;
 
    if checkbox2.Checked then
    begin
     AdoDataset1.Filtered := false;
   Adodataset1.Filter := 'number like ''%' + form3.Edit1.text + '%''';
   AdoDataset1.Filtered := True;
    end;
   end;
       end;
 
   if adodataset1.RecordCount < 0 then
    begin
        Adodataset1.Filtered := false;
        ShowMessage ('В базе данных нет записей, удоволетворяющих критерию запроса');
    end;
   end;
 
procedure TForm1.CheckBox1Click(Sender: TObject);
begin
 
   begin
if checkbox1.Checked then checkbox2.Enabled := false else checkbox2.Enabled := true;
if checkbox1.Checked then checkbox3.Enabled := false else checkbox3.Enabled := true;
   end;
  end;
 
procedure TForm1.CheckBox2Click(Sender: TObject);
begin
 
 
   begin
if checkbox2.Checked then checkbox1.Enabled := false else checkbox1.Enabled := true;
if checkbox2.Checked then checkbox3.Enabled := false else checkbox3.Enabled := true;
   end;
 
end;
 
procedure TForm1.CheckBox3Click(Sender: TObject);
begin
 
   begin
if checkbox3.Checked then checkbox1.Enabled := false else checkbox1.Enabled := true ;
if checkbox3.Checked then checkbox2.Enabled := false else checkbox2.Enabled := true;
   end;
 
 
 
end;
 
procedure TForm1.FormActivate(Sender: TObject);
begin
form1.Caption := 'BDEdit';
   try
     ADOCOnnection1.Open;
     ADODataSet1.Active := true;
   except
      on e:Exception do begin
        DBGrid1.Enabled := false;
        MessageDlg ('Нет файла C:\1.mdb', mtError, [mbOK], 0);
      end;
 
   end;
 
end;
 
procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
if DBGrid1.EditorMode then
   begin
     ADOdataset1.UpdateBatch(arCurrent);
   end;
end;
 
 
 
procedure TForm1.newClick(Sender: TObject);
var
r: integer;
begin
 if DBGrid1.EditorMode then
 begin
    r:= MessageDlg('БД редактируется.Создать новый документ' + #10 + 'без сохранения изменений в текущем?',mtWarning,[mbYes,mbNo],0, mbNo);
    if r = mrYes then
    DBGrid1.CleanupInstance;
 end;
end;
 
 
 
end;
end.

if opendialog1.execute then
if length(opendialog1.files[0])<>0 then
begin
adoconnection1.close;
adoconnection1.connectionstring:='Provider=Microsoft.Jet.OLEDB.4.0;Data Source='+ opendialog1.filename+  ';Persist Security Info=False';
adoconnection1.open;
end;