uses graph,crt;
var gd,gm,y,x:integer;
    pressedkey:char;
   label 0,1,2;
begin
initgraph(gd,gm,'c:\bp\bgi');
ellipse (320, 240, 360, 0, 28,200);
y:= 440;
outtext('Press up arrow key for moving up/down arrow key for moving down');
outtextxy(1,10,'Press Esc to exit');
0:
pressedkey:=readkey;
if pressedkey=chr(27) then halt;
if ord(pressedkey)=72 then goto 1;
if ord(pressedkey)=80 then goto 2;
goto 0;
1:
x:= 320;
y:= y - 2;
IF y < 45 THEN y:= 47;
putpixel (x, y, 13);
goto 0;
2:
putpixel (x, y, 0);
x:= 320;
y:= y + 2;
IF y > 440 THEN y:= 442;
putpixel(x, y, 0);
goto 0;
repeat;
until keypressed;
closegraph;
end.