Tic tac toe in pascal by me

Iseng-iseng ga ada kerjaan, gimana cara nambahin pemain komputer ya?

program CaturJawa2player2009gilang;

uses

wincrt;

var

i:integer;

Papan:array [1..9] of char;

x:integer;

y:integer;

z:integer;

label

balik,balik1,balik2;

(*prosedur-prosedur*)

procedure kosong;

begin

for i:=1 to 9 do

papan[i]:=’_’;

end;

procedure cetak;

begin

for i:= 1 to 3 do

write(papan[i]);

writeln;

for i:= 4 to 6 do

write(papan[i]);

writeln;

for i:=7 to 9 do

write(papan[i]);

end;

procedure tulisx (x:integer);

begin

papan[X]:=’X’;

end;

procedure tulisy(y:integer);

begin

papan[y]:=’O’;

end;

begin

writeln(‘program tic-tac-toe’);

writeln(‘2009 by gilang’);

writeln(‘versi 0.1’);

kosong;

cetak;

z:= 0;

balik:

if odd(z) then

begin

writeln;

writeln(‘giliran anda, O!’);

balik2:

writeln(‘masukan nomor kotak’);

read(y);

tulisy(y);

cetak;

z:=z+1;

goto balik;

end

else

begin

writeln;

writeln(‘giliran anda,X!’);

balik1:

writeln(‘silahkan masukan nomor kotak’);

read(x);

tulisx(x);

cetak;

z:=z+1;

goto balik;

end;

end.