procedure ChangeDBNavImage(DBnav: TDbNavigator);
var
 i: Integer;
 tempGlyph: TBitmap;
 ExePath: string;
begin
 ExePath := ExtractFilePath(Application.ExeName);
 tempGlyph := TBitmap.Create;
 try
  with DBNav do
  begin
  for i := 0 to ControlCount - 1 do
  begin
  if Controls[i].ClassName = 'TNavButton' then
  begin
  case TNavButton(Controls[i]).Index of
  nbFirst: tempGlyph.LoadFromFile(ExePath + 'first.bmp');
  nbPrior: tempGlyph.LoadFromFile(ExePath + 'previous.bmp');
  nb: tempGlyph.LoadFromFile(ExePath + '.bmp');
  nbLast: tempGlyph.LoadFromFile(ExePath + 'Last.bmp');
  nbInsert: tempGlyph.LoadFromFile(ExePath + 'Insert.bmp');
  nbDelete: tempGlyph.LoadFromFile(ExePath + 'Delete.bmp');
  nbEdit: tempGlyph.LoadFromFile(ExePath + 'Edit.bmp');
  nbPost: tempGlyph.LoadFromFile(ExePath + 'Post.bmp');
  nbCancel: tempGlyph.LoadFromFile(ExePath + 'Cancel.bmp');
  nbRefresh: tempGlyph.LoadFromFile(ExePath + 'Refresh.bmp');
  end;
  TNavButton(Controls[i]).Glyph := tempGlyph;
  end;
  end;
  end;
 finally
  tempGlyph.Free;
 end;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
 ChangeDBNavImage(DBNavigator1);
end;