Uses Graph, CRT;

Type
  TSetGraph =
    Object
      xst, yst, xfn, yfn: Integer;

      Procedure Init(pxst, pySt, pxfn, pyfn: Integer);
      Procedure Hide;
      Procedure Show(Color: Integer);
      Procedure Move(pxst, pySt, pxfn, pyfn: Integer);
    End;

Procedure TSetGraph.Init(pxst, pySt, pxfn, pyfn: Integer);
  Begin
    xst := pxst; xfn := pxfn;
    yst := pyst; yfn := pyfn;
  End;

Procedure TSetGraph.Hide;
  Begin
    Setcolor(Black);
    Rectangle(xst, yst, xfn, yfn)
  End;

Procedure TSetGraph.Show;
  Begin
    SetColor(Color);
    Rectangle(xst, yst, xfn, yfn)
  End;

Var
  d,r: Integer;{px1,px2,py1,py2,pcolor: integer;}
  pColor: Integer;

Procedure TSetGraph.Move;
  Begin
    Hide;
    Inc(xst, pxst);
    Inc(xfn, pxfn);
    Inc(yst, pyst);
    Inc(yfn, pyfn);
    Show(pColor);
end;

Var
 sg: TSetGraph;
 begin
 d:=detect;
 initgraph(d,r,'');

 sg.Init( (GetMaxX div 5)*3, (GetMaxY div 5)*3,
          4*(GetMaxX div 5)*3, 4*(GetMaxY div 5)*3);

 pColor:=3;

 sg.show(pColor);
 repeat begin
 if keypressed then begin
 case readkey of
 #77: sg.move(1,0,1,0);
 #75: sg.move(-1,0,-1,0);
 #80: sg.move(0,1,0,1);
 #72: sg.move(0,-1,0,-1);
 end
 end
 end until readkey=#27;
 closegraph;
 end.