Program Myprog;
uses Graph,crt;
var
a,b, gd,gm,ecode: Integer;
begin
gd := Detect;
InitGraph(gd, gm,' ');
ecode:=GraphResult;
if ecode<>grOK then
begin
Writeln('Graphics error:', GraphErrorMsg(ecode));
exit;
end;
for b:=100 to 300 do
begin
for a:=1 to 15 do
begin
SetLineStyle(0,2,a);
circle(420,340,b);
circle(420,340,b-100);
circle(420,340,b-80);
circle(420,340,b-60);
circle(420,340,b-40);
circle(420,340,b-20);
setcolor(a);
delay(2);
ClearDevice ;
end;
end;
readln;
closegraph;
end.
