[DM2005]

paso a descriir mi procedure,

Código Delphi [-]
procedure TForm1.ListBox1DblClick(Sender: TObject);
begin
  Panel6.Visible := False;
  Panel7.Visible := True;
  if ListBox1.ItemIndex = 0 then
    begin
       ListBox2.Clear;
       ListBox2.Items.LoadFromFile('C:\IPCapitulo.txt');
       ListBox3.Items.LoadFromFile('C:\IPArquivo.txt');
       ListBox4.Items.LoadFromFile('C:\IPMaximizada.txt');
 end;
  if ListBox1.ItemIndex = 1 then
    begin
       ListBox2.Clear;
       ListBox2.Items.LoadFromFile('C:\IPCapitulo.txt');
       ListBox3.Items.LoadFromFile('C:\IPArquivo.txt');
       ListBox4.Items.LoadFromFile('C:\IPMaximizada.txt');
 end;
.
.
.
.
.
end;

Código Delphi [-]
{$WRITEABLECONST ON}
procedure TForm1.SpeedButton2Click(Sender: TObject);
const
  i: integer = 0;
begin
   with ListBox3.Items do
    begin
      if ListBox3.ItemIndex < Count-1
         then ListBox2.ItemIndex := ListBox2.ItemIndex + 1
         else MessageDlg('Você já está no final do curso !',mtInformation,[mbOk],0);
         Panel2.Caption := ListBox2.Items.Strings[ListBox2.ItemIndex];
         WebBrowser1.Navigate(strings[ListBox2.ItemIndex]);
    end;
    begin
     with ListBox4 do
        begin
         if i < Count then
          if Items[i] = 'N' then
           begin
             Self.Height := 300;
             Self.Width := 550;
             Self.Left := 400;
             Self.Top := 400;
           end;
          if Items[i] = 'S' then
           begin
             Self.Height := 739;
             Self.Width := 1024;
             Self.Left := 0;
             Self.Top := 0;
           end;
         if i < Count-1 then
            inc(i)
         else
            i:= ListBox4.ItemIndex;
        end;
    end;
end;
{$WRITEABLECONST OFF}

espero ayude a entender,
gracias
saludos