ООП - падает программа при вводе данных

type
  TKart = class
  public
  rooms, etazh : integer;
  s : Double;
  adres : string;
  Constructor Init;
  Destructor Done;
  procedure setob();
  procedure getob();
  function obmen(ob :TKart):Boolean;
end;

procedure TKart.setob;
begin
  Write('Kol-vo komnat: '); readln(rooms);
  Write('Etazh: '); Readln(etazh);
  Write('Ploshad: '); Readln(s);
  write('Adres: '); Readln(adres);
end;

type
  TKart = class
  public
  rooms, etazh : integer;
  s : Double;
  adres : string;
  Constructor Init;
  Destructor Done;
  procedure setob();
  procedure getob();
  procedure setobb(r,e : Integer; ss:Double; a:string);
  function obmen(ob :TKart):Boolean;
end;
 
constructor TKart.Init();
begin
   rooms := 0; etazh := 0; s := 0.0;
   adres := '';
end;
 
destructor TKart.Done();
begin
   rooms := 0; etazh := 0; s := 0.0;
   adres := '';
end;
 
procedure TKart.setob;
var
  r,e:Integer;
  ss:double;
  a:string;
begin
  Write('Kol-vo komnat: '); Readln(r); //rooms := 3;//readln(Self^.rooms);
  Write('Etazh: ');  Readln(e); //Readln(etazh);
  Write('Ploshad: '); Readln(ss);//Readln(s);
  write('Adres: '); Readln(a);//Readln(adres);
  setobb(r,e,ss,a);
  Writeln('_______________________');
end;
 
procedure TKart.setobb(r,e : Integer; ss:Double; a:string);
begin
  rooms := r;
  etazh := e;
  s := ss;
  adres := a;
end;
 
 
procedure TKart.getob;
begin
  Writeln('Kol-vo komnat: ',rooms);
  Writeln('Etazh: ',etazh);
  Writeln('Ploshad: ',s);
  writeln('Adres: ',adres);
  Writeln('_______________________');
end;
 
 
function TKart.obmen(ob : TKart):Boolean;
begin
  if (rooms = ob.rooms) and (etazh = ob.etazh) then
    if (s >= (ob.s - ob.s/10)) then
      if (s <= (ob.s + ob.s/10)) then
        Result := true;
  Result := false;
end;
 
procedure _del(var mas:array of TKart; i,n:Integer);
var
  j:Integer;
begin
  for j:=i to n-1 do
    mas[j] := mas[j+1];
end;
 
 
var
  krt,obmn: array[1..100] of TKart;
  i,j,ko,kk,cmd,n:integer;
  ff,f:Boolean;
 
  r,e:Integer;
  ss:double;
  a:string;
begin
ko := 1;
kk := 1;
f := true;
ff := True;
while (f) do begin
//  clrscr;
  Writeln('1: Dobavlenie zapisi v kartoteku');
  Writeln('2: Dobavlenie zayavki');
  Writeln('3: Poisk v kartoteki variantov na obmen');
  Writeln('4: vivod vsego spiska');
  Writeln('0: Exit');
  Readln(cmd);
  case cmd of
    1: begin
      Writeln('DOBAVLENIE ZAPISI V KARTOTEKU');
      Write('kol-vo zapisei');
      Readln(n);
      for i := 1 to n do begin
        Write('Kol-vo komnat: '); Readln(r); //rooms := 3;//readln(Self^.rooms);
        Write('Etazh: ');  Readln(e); //Readln(etazh);
        Write('Ploshad: '); Readln(ss);//Readln(s);
        write('Adres: '); Readln(a);//Readln(adres);
        krt[kk].setobb(r,e,ss,a);
        Writeln('_______________________');
      end;
    end;
    2 : begin
      Writeln('DOBAVLENIE ZAYAVKI NA OBMEN');
      Write('kol-vo zayavok');
      Readln(n);
      for i := 1 to n do begin
        obmn[ko].setob;
        ko:=ko+1;
      end;
    end;
    3 : begin
      ff := false;
      for i:=1 to kk do begin
        for j:=1 to ko do begin
          if (krt[i].obmen(obmn[j])) then begin
            Writeln('OBMEN');
            krt[i].getob;
            Writeln('NA');
            obmn[j].getob;
            _del(krt,i,kk);
            _del(obmn,j,ko);
            ff := true;
            ko:=ko-1;
            kk:=kk-1;
          end;
        end;
      end;
      if (not ff) then Writeln('Podhodyashih variantov net!');
    end;
    4: begin
      if kk=0 then writeln('Kartoteka pusta')
      else begin
      for i:=0 to kk do
        krt[kk].getob;
       end;
     end;
    0 : begin
      f := false;
      exit;
    end;
  end;
end;
  readln;
end.