Программа не работает в Turbo но работает в ABC

program practychna3;
uses crt;
label metka;
const a=-PI; b=PI;dx=PI/32;
var x,y:real;
n,k :word;
ch :char;
i,kr :byte;
begin
n:=round((b-a)/dx);
metka:
clrscr;
writeln('1-Repeat');
writeln('2-While...do');
writeln('3-For');
writeln('4-Exit');
write('case punkt?->');
ch:=readkey;
case ch of
'1':begin
clrscr;
writeln('_____REPEAT_____');
x:=a;
kr:=0;
repeat
begin
if x>=0 then y:=2*sqr(sin(x))*sin(x)
else y:=-sqr(cos(x)/sin(x));
if kr<22 then
writeln('y(',x:0:1,')=',y:6:2)
else
begin
writeln('___press any key to see next page___');
readkey;
clrscr;
kr:=0;
writeln('y(',x:0:1,')=',y:6:2);
end;
x:=x+dx;
inc(kr);
end;
until x>=b;
writeln('___Press any key___');
readkey;
goto metka;
end;
'2':begin
clrscr;
writeln('_____WHILE...DO_____');
kr:=0;
x:=a;
while x<=b do
begin
if x>=0 then y:=2*sqr(sin(x))*sin(x)
else y:=-sqr(cos(x)/sin(x));
if kr<22 then
writeln('y(',x:0:1,')=',y:6:2)
else
begin
writeln('___press any key to see next page___ ');
readkey;
clrscr;
kr:=0;
writeln('y(',x:0:1,')=',y:6:2);
end;
x:=x+dx;
inc(kr);
end;
writeln('___Press any key___');
readkey;
goto metka;
end;
'3':begin
clrscr;
x:=a;
kr:=0;
writeln('_____FOR_____');
for i:=1 to n+1 do
begin
if x>=0 then y:=2*sqr(sin(x))*sin(x)
else y:=-sqr(cos(x)/sin(x));
if kr<22 then writeln('y(',x:0:1,')=',y:6:2)
else
begin
writeln('___press any key to see next page___');
readkey;
clrscr;
kr:=0;
writeln('y(',x:0:1,')=',y:6:2);
end;
x:=x+dx;
inc(kr);
end;
writeln('___Press any key___');
readkey;
goto metka;
end;
'4':Exit
else
begin
clrscr;
writeln('!!!error!!!');
write('___Press any key___');
readkey;
goto metka;
end;
end;
end.