Где допущена ошибка?

uses crt;
type
 p=^cars;
 cars=record
  mark:string;
  year:integer;
  price:integer;
  class:string;
  next:p;
  prev:p;
  end;
 
var head:p;
    key:char;
 
procedure create(var ahead:p);
var cur,p1:p;
    i:integer;
    key2:char;
begin
i:=2;
if ahead=nil then
    begin
    new(ahead);
    writeln('1-ya zapis:');
    write('Marka:');
    readln(ahead^.mark);
    write('God');
    readln(ahead^.year);
    write('Klass:');
    readln(ahead^.class);
    write('Cena:');
    readln(ahead^.price);
    ahead^.next:=nil;
    ahead^.prev:=nil;
    end
else
    begin
    cur:=ahead;
    while cur^.next<>nil do
    begin
    inc(i);
    cur:=cur^.next;
    end;
 
    new(p1);
    cur^.next:=p1;
    p1^.next:=nil;
    p1^.prev:=cur;
    cur:=p1;
    writeln(i,'-ya zapis:');
    write('Marka:');
    readln(cur^.mark);
    write('God:');
    readln(cur^.year);
    write('Klass:');
    readln(cur^.class);
    write('Cena:');
    readln(cur^.price);
 
   end;
 
end;
 
procedure del(var ahead:p);
var cur,p1:p;
    num,numd,count:integer;
begin
count:=0;
cur:=ahead;
 
while cur<>nil do
begin
cur:=cur^.next;
inc(count);
end;
 
numd:=1;
repeat
write('VVedite nomer udalyaemoi zapisi:');
read(num);
if (num>count)or(num<0)then
 begin
 clrscr;
 writeln('Dannoi zapisi net');
 end;
until (num>0)and(num<=count);
 
if (num>1) then begin
cur:=ahead;
 
while numd<num-1 do
begin
cur:=cur^.next;
inc(numd);
end;
 
p1:=cur^.next;
cur^.next:=cur^.next^.next;
cur:=cur^.next;
cur^.prev:=cur^.prev^.prev;
dispose(p1);
end;
 
if num=1 then
begin
cur:=ahead^.next;
cur^.prev:=nil;
p1:=ahead;
ahead:=cur;
dispose(p1);
end;
 
end;
 
procedure view(ahead:p);
var cur:p;
    i:integer;
begin
cur:=ahead;
i:=0;
while cur<>nil do
begin
inc(i);
writeln(i,'-ya zapis:');
writeln('Marka:',cur^.mark);
writeln('God',cur^.year);
writeln('Klass:',cur^.class);
writeln('Cena:',cur^.price);
writeln;
cur:=cur^.next;
end;
end;
 
begin
head:=nil;
clrscr;
create(head);
repeat
key:=readkey;
case key of
#13:begin
    clrscr;
    create(head);
    end;
 
'z':begin
    clrscr;
    view(head);
    end;
 
'x':begin
    clrscr;
    del(head);
    end;
end;
until key=#27;
end.

read(a);
read(b);
read(c);
readln;

readln(a,b,c);