Compiler fint, men masser af fejl?

Hej,

Jeg er i gang med et lille vendespil.
Det compiler uden det mindste brok, men jeg får flere fejl under kørslen. Bl.a. en abstract error.

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, ExtCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    ListBox1: TListBox;
    Timer1: TTimer;
    Timer2: TTimer;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure MyOnClick(Sender: TObject);
    procedure FormDblClick(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
    procedure del(lvl: integer);
    procedure Timer2Timer(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  Level, point, par: real;
  Last: String;
  lastobj, newobj: TObject;

implementation

{$R *.dfm}

procedure TForm1.MyOnClick(Sender: TObject);
var
 slet, skjul: boolean;
begin
slet := false;
skjul := false;

if Sender <> lastobj then
begin
 If (Sender is TImage) then    // Is it a image?
  begin
   (Sender as TImage).Picture.LoadFromFile('tema\\1\\billeder\\'+ListBox1.Items[strtoint((Sender as TImage).Hint)-1]);
   if last <> '' then
    begin
     if last = ListBox1.Items[strtoint((Sender as TImage).Hint)-1] then
      begin
       point := point + level;
       Form1.Caption := 'Point: '+floattostr(point);
       //last := '';
       //sleep(500);
       slet := true;
       //(Sender as TImage).Picture.LoadFromFile('tema\\1\\billeder\\bag.bmp');
       //(lastobj as TImage).Picture.LoadFromFile('tema\\1\\billeder\\bag.bmp');
      end
     else
      begin
       if ListBox1.Items[strtoint((Sender as TImage).Hint)-1] = 'joker.bmp' then
        begin
         point := point + (level*2);
         Form1.Caption := 'Point: '+floattostr(point);
         newobj := Sender;
         timer2.Enabled := true;
        end
       else
        begin
         //last := '';
         //sleep(500);
         slet := false;
         skjul := true;
         //(Sender as TImage).Picture.LoadFromFile('tema\\1\\billeder\\bag.bmp');
         //(lastobj as TImage).Picture.LoadFromFile('tema\\1\\billeder\\bag.bmp');
        end;
      end;
    end
   else
    begin
     if ListBox1.Items[strtoint((Sender as TImage).Hint)-1] = 'joker.bmp' then
      begin
       point := point + (level*2);
       Form1.Caption := 'Point: '+floattostr(point);
       newobj := Sender;
       timer2.Enabled := true;
      end
     else
      begin
       last := ListBox1.Items[strtoint((Sender as TImage).Hint)-1];
       lastobj := Sender;
       slet := false;
       skjul := false;
      end;
    end;
  end;

if slet then
 begin
  par := par+1;
  (Sender as TImage).Free;
  if last <> '' then
   begin
    (lastobj as TImage).Free;
   end;
  last := '';
  if par = int(((level+1)*(level+1)) / 2) then
   begin
    showmessage('Du har klaret level '+floattostr(level)+' og har nu '+floattostr(point)+' point.');
    par := 0;
    //slet := false;
    //skjul := false;
    last := '';
    level := level + 1;
    del(strtoint(floattostr(level)));
   end;
 end
else
 begin
  if skjul then
   begin
    newobj := Sender;
    last := '';
    timer1.Enabled := true;
   end;
 end;

end;

end;

procedure TForm1.del(lvl:integer);
var
 i, j, k: integer;
begin

 Form1.ListBox1.Items.LoadFromFile('tema\\1\\settings\\levels\\'+floattostr(lvl)+'.txt');
 Randomize;
 for k := 1 to Form1.ListBox1.Items.Count do
  Form1.ListBox1.Items.Move(Random(Form1.ListBox1.Items.Count), 0);

 for i := 1 to lvl + 1 do
  begin
   for j := 1 to lvl + 1 do
    begin
     with TImage.Create(form1) do
      begin
       Parent := Form1;
       Width := ( 420 - ( ( lvl + 2 ) * 4 ) ) div ( lvl + 1);
       Height := Width;
       Left := j * 4 + ( Width * ( j - 1 ) );
       Top := i * 4 + ( Height * ( i - 1 ) );
       Hint := inttostr( j + ( ( i - 1 ) * ( lvl + 1 ) ) );
       Name := 'Image'+inttostr( j + ( ( i - 1 ) * ( lvl + 1 ) ) );
       OnClick := Form1.MyOnClick;
       Stretch := true;
       Picture.LoadFromFile('tema\\1\\billeder\\bag.bmp');
       Visible := True;
      end;
    end;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
 Button1.Enabled := false;
 del(strtoint(floattostr(Level)));
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
 Level := 1;
 Button1.Visible := false;
 del(strtoint(floattostr(Level)));
 Form1.Color := clBlack;
 Form1.ClientWidth := 420;
 Form1.ClientHeight := 420;
end;

procedure TForm1.FormDblClick(Sender: TObject);
begin
 //Form1.Close;
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
timer1.Enabled := false;
(newobj as TImage).Picture.LoadFromFile('tema\\1\\billeder\\bag.bmp');
(lastobj as TImage).Picture.LoadFromFile('tema\\1\\billeder\\bag.bmp');
end;

procedure TForm1.Timer2Timer(Sender: TObject);
begin
timer2.Enabled := false;
(newobj as TImage).Free;
if last <> '' then
 begin
  last := '';
  (lastobj as TImage).Picture.LoadFromFile('tema\\1\\billeder\\bag.bmp');
 end
else
 begin
  last := '';
 end;
end;

end.

Jeg ville gerne ligge det hele op inkl. billeder og andre filer, men det kan jeg desværre ikke via skolens net.

Håber i kan hjælpe mig.

Fejl koder jeg får:

Access violation at address 00004010 in module 'Project1.exe'. Read of address 00004010.

Access violation at address 00403349 in module 'Project1.exe'. Read of address 00000033.

Access violation at address 00403349 in module 'Project1.exe'. Read of address 00003A98.

Access violation at address 00403342 in module 'Project1.exe'. Read of address FFFFFFD1.

Access violation at address 00403342 in module 'Project1.exe'. Read of address FFFFFFD0.

Access violation at address 00403340 in module 'Project1.exe'. Read of address 00000001.

Access violation at address 00403350 in module 'Project1.exe'. Read of address 00153000.

Abstract Error.

De kommer ikke alle hver gang, og det er tilfældigt hvornår i spillet de kommer. Den mest hyppige er:

Access violation at address 00403349 in module 'Project1.exe'. Read of address 00003A98.

M.v.h. Johnny.

På forhånd tak!