procedure TForm1.Button1Click(Sender: TObject);
  var v_usia : integer;
  var v_harga : real;
  var v_diskon : real;
begin

  IF ComboBox1.Text = 'Jakarta-Surabaya' THEN
  begin
    IF ComboBox2.Text = 'Kereta' THEN v_harga := 250000
    ELSE IF ComboBox2.Text = 'Bus' THEN v_harga := 300000
    ELSE IF ComboBox2.Text = 'Pesawat' THEN v_harga := 450000
    ELSE v_harga := 0;
  end
  ELSE IF ComboBox1.Text = 'Jakarta-Padang' THEN
  begin
    IF ComboBox2.Text = 'Kereta' THEN v_harga := 0
    ELSE IF ComboBox2.Text = 'Bus' THEN v_harga := 350000
    ELSE IF ComboBox2.Text = 'Pesawat' THEN v_harga := 500000
    ELSE v_harga := 400000;
  end;

  v_usia := strtoint(usia.Text);
  IF v_usia < 10 THEN
    v_diskon := v_harga * 0.1;


harga.Text := floattostr(v_harga);
diskon.Text := floattostr(v_diskon);
total.Text := floattostr(v_harga - v_diskon);

end;