Pascal/Turbo Pascal - error en areas

Var

  radio: real;

  area: integer;

  perimetro: integer;

  pi:real;

  tonta: integer;

begin

  writeln ('radio?');

  read (radio);

  writeln('perimetro o area?');

  if not perimetro then

     area:=radio^2*pi

  else

    perimetro:=2radio*pi;

  read (tonta);

end.

{Mira esto}

Var

  radio: real;

  area: integer;

  perimetro: integer;

  pi:real;

  tonta: integer;

begin

  writeln ('radio?');

  read (radio);

  writeln('perimetro o area?');

  if not perimetro then

   begin

     area := 3.1416 * (radio * 2);

      writeln(area);

    end

  else

       begin

            perimetro := (2 * 3.1416) * radio;

             writeln(perimetro);

  readln;

end.

{Esto es lo que pides}

uses

   crt;

Var

radio: real;

area: real;

perimetro: real;

pi:real;

tonta: integer;

tt : char;

begin

clrscr;

perimetro := 0.0;

write('radio?');

readln(radio);

writeln('[P]=perimetro  [A]=area');

repeat

    tt := upcase(readkey);

until tt in['P','A'];

if  tt = 'A' then

begin

area := 3.1416 * (radio * radio);

writeln('  El Area Es = ',area:0:4);

end

else

begin

perimetro := (2 * 3.1416) * radio;

writeln('   El Perimetro Es = ',perimetro:0:4);

end;

readln;

end.