Паскаль.Обработка массивов

uses crt;
label metka;
type student =
  record
    surname: string[32];
    fname: string[32];
    middle_name: string[32];
    student_ID_card: string[32];
    form_of_education: string[32];
    order_number: string[32]
  end;
var group: array [1..50] of student;
    i: integer;
    a: string;
    ch :char;
begin
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('Vvedit` dani pro studentiv(ne bil`she 50):');
  i := 0;
  repeat
    inc(i);
    writeln('Nomer', i);
    write('Prizvycshe'); readln(group[i].surname);
    write('Im`ia'); readln(group[i].fname);
    write('Po-bat`kovi'); readln(group[i].middle_name);
    write('student_ID_card '); readln(group[i].student_ID_card);
    write('Phorma navchannia'); readln(group[i].form_of_education);
    write('Nomer zakaza '); readln(group[i].order_number);
    write('Prodolzhyt` '); readln(a);
    if length(a) = 0 then a := 'Д';
  until (i >= 50) or (a[1] in ['n', 'N', 'н', 'Н']);
  writeln('Stvoreno ', i, ' zapysiv');
  readln;
 
writeln('___Press any key___');
readkey;
goto metka;
end;
'2':begin
 
 
 
 
writeln('___Press any key___');
readkey;
goto metka;
end;
'3':begin
 
 
 
 
 
 
writeln('___Press any key___');
readkey;
goto metka;
end;
'4':Exit
else
begin
clrscr;
writeln('!!!error!!!');
write('___Press any key___');
readkey;
end;
end;
end.