MId klass A 2010

uses crt;
type
                  mahasiswa = record
                    nim                    : integer;
                    nama                   : string [15];
                    mid,ns,na              : real;
                    end;
var
   filemahasiswa        : file of mahasiswa;
   recordmahasiswa      : mahasiswa;
   lagi                 : char;
begin
assign(filemahasiswa,'MHS.DAT');
rewrite(filemahasiswa);
lagi :='Y';
while upcase(lagi)='Y' do
begin
clrscr;
with recordmahasiswa do
begin
READ;
     gotoxy(5,6); writeln('Nim Mahasiswa        :');
     gotoxy(5,8); writeln('Nama Mahasiswa       :');
     gotoxy(5,10);writeln('Nilai Mid            :');
     gotoxy(5,12);writeln('Nilai Semester       :');
     gotoxy(5,13);writeln('----------------------');

     gotoxy(27,6);    readln(nim);
     gotoxy(27,8);    readln(nama);
     gotoxy(27,10);   readln(mid);
     gotoxy(27,12);   readln(ns);
     writeln;
     na := (mid + ns)/2;
     writeln;
     gotoxy(5,15); writeln('----------------------');
     gotoxy(5,16); writeln('nilai ahir (na)=',na:5:2);
     gotoxy(5,17); writeln('----------------------');
     end;

write(filemahasiswa, recordmahasiswa);
gotoxy(5,19);write('masukkan data lagi (Y/T) ?'); readln(lagi);
end;
close(filemahasiswa);
end.