uses crt;

type
  MenuType = (Vertical);

const
  width = 12;
  nItems = 3;
  optNormal = LightGray;
  optSelected = Yellow;

var
  X, Y,
  selected,
  row: integer;
  _style: MenuType;

procedure MakeMenu (optText: array of string; MaxItems: integer);
var
  i, _X: byte;
begin
  Y := row;
  _X := X;
  for i := 0 to MaxItems-1 do
  begin
    GoToXY (_X, Y);
    if i = selected then
      TextColor (optSelected)
    else
      TextColor (optNormal);
    write (optText[ i ]);
    inc (Y, 2);
  end;
end;

function MenuOption (var optText: array of string; MaxItems: integer): byte;
var
  ch: char;
begin
  selected := 0;
  X := (80 - width) div 2;
  row := (25 - MaxItems) div 2;
  repeat
    MakeMenu (optText, MaxItems);

    ch := readkey;
    if ch = #0 then
      ch := readkey;

    case ch of
      #80, #77: {Down/Right}
      begin
        inc (Selected);
        if Selected = MaxItems then
          Selected := 0;
        MakeMenu (optText, MaxItems);
      end;
    end;
  until ch = #13;
  MenuOption := Selected + 1;
  TextColor (optNormal);
  clrscr;
end;

type
  tprocedure = procedure;


Procedure ShowMenu(s:array of string; proc: array of tprocedure);
var
  Option,i: byte;
begin
  _style := Vertical;
  repeat
    clrscr;
    Option := MenuOption (s, nItems);

    proc[pred(option)];
  until Option = nItems;
end;


procedure do_termini; far; forward;
procedure do_subs; far; forward;
procedure do_data_view; far; forward;
procedure do_data_add; far; forward;
procedure do_nothing; far; forward;

const
   s: array [1..3] of string=('termini','podprogrammi','exit');
   s_proc: array[1 .. 3] of tprocedure = (do_termini, do_subs, do_nothing);

   t: array[1..3] of string=('Prosmotr dannih','Dobavlenie dannih','Vozvrat v menu');
   t_proc: array[1 .. 3] of tprocedure = (do_data_view, do_data_add, do_nothing);

   r: array[1 .. 3] of string = ('sub_1', 'sub_2', 'exit');
   r_proc: array[1 .. 3] of tprocedure = (do_nothing, do_nothing, do_nothing);


procedure do_termini;
begin
  ShowMenu(t, t_proc);
  { ... }
end;
procedure do_subs;
begin
  { ... }
end;

procedure do_data_view;
begin
  showmenu(r, r_proc);
  { ... }
end;
procedure do_data_add;
begin
  { ... }
end;

procedure do_nothing;
begin end;


begin
  showMenu(s, s_proc);
end.