program dan design

uses crt;
label
aw,ak;
var
np,nb:string;
kode,lagi:char;
lm,jm:integer;
tot,dis,sewa1,sewa2,biaya:real;
begin
aw:
clrscr;
writeln('-------------------------------');
writeln(' DAFTAR BUS PARIWISATA ');
writeln('-------------------------------');
writeln(' 1. HIBA UTAMA ');
writeln(' 2. BIG BIRD ');
writeln(' 3. STEADY SAFE ');
writeln(' 4. PRIMA JASA ');
writeln('-------------------------------');
write(' Masukkan Nama Penyewa : ');readln(np);
write(' Masukkan Kode Bus : ');readln(kode);
write(' Masukkan Lama Sewa : ');readln(lm);
case kode of
'1': begin
nb:='Hiba Utama';
sewa1:=750000;
sewa2:=80000;
end;
'2': begin
nb:='Big Bird';
sewa1:=950000;
sewa2:=88000;
end;
'3': begin
nb:='STEADY SAFE';
sewa1:=700000;
sewa2:=75000;
end;
'4': begin
nb:='PRIMA JASA';
sewa1:=800000;
sewa2:=70000;
end;
end;
if lm<10 then
begin
biaya:=sewa1;
dis:=0*biaya;
end
else if lm>48 then
begin
biaya:=((lm-10)*sewa2)+sewa1;
dis:=0.1*biaya;
end
else
begin
biaya:=((lm-10)*sewa2)+sewa1;
dis:=0*biaya;
end;
tot:=biaya-dis;
clrscr;
writeln;
writeln(' PROGRAM PENYEWAAN BUS PARIWISATA ');
Writeln('=======================================');
writeln('Nama Penyewa = ',np);
writeln('Kode Bus = ',kode);
writeln('Nama Bus = ',nb);
writeln('Lama Sewa = ',lm);
writeln('Biaya Sewa 10 Jam Pertama = Rp.',sewa1:1:0);
writeln('Biaya Sewa = Rp.',biaya:1:0);
writeln('Discount = Rp.',dis:1:0);
writeln('=======================================');
Writeln('Total Biaya Sewa = Rp.',tot:1:0);
writeln('=======================================');
write('Mau Input Lagi =');readln(lagi);
if upcase (lagi)='y' then
goto aw
else
goto ak;
readln;
ak: