Выдаёт ошибку в строке Activ.Y:=-1, что делать?

unit Unit1;
 
interface
 
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ExtCtrls;
 
type
  TForm1 = class(TForm)
    Timer1: TTimer;
    procedure FormCreate(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
 
var
  Form1: TForm1;
  Buf, Pole:TBitmap;
  Img:array[1..12] of TBitmap;
  map:array[0..7,0..7] of Integer;
  way:array[0..7,0..7] of Boolean;
  Current:integer;
  path:string;
  Activ:TPoint;
 
implementation
 
{$R *.dfm}
 
procedure TForm1.FormCreate(Sender: TObject);
var i,j:integer;
begin
 
 path:=ExtractFileDir(Application.ExeName);
 
  For i:=1 to 12 do
begin
    Img[i]:=TBitmap.Create;
    Img[i].Transparent:=True;
    Img[i].LoadFromFile(path+'\img\'+inttostr(i)+'.bmp');
end;
    Pole:=TBitmap.Create;
    Pole.LoadFromFile(path+'\img\pole.bmp');
 
    Buf:=TBitmap.Create;
    Buf.Width:=640;
    Buf.Height:=480;
 
    Current:=1;
    Activ.X:=-1
    Activ.Y:=-1;
 
    For i:=0 to 7 do
    For j:=0 to 7 do
     begin
       map[i,j]:=0;
       way[i,j]:=false;
   end;
    end;
 
procedure TForm1.Timer1Timer(Sender: TObject);
begin
  buf.Canvas.Draw(0,0,Pole);
 
  form1.Canvas.Draw(0,0,Buf);
 
 
 
 
 
end;
 
end.