link graphics
$define Width 500
$define Height 500
procedure main() # target
    WOpen("size="||Width||","||Height, "drawop=reverse")
    
    x := ?Width; y := ?Height; r := 50
    repeat {
        DrawCircle(x, y, r)
        hit := &null
        every 1 to 80 do {
            WDelay(10)
            while *Pending() > 0 do {
                if Event()=== &lpress then {
                    if sqrt((x-&x)^2+(y-&y)^2) < r then {
                        FillCircle(x,y, r)
                        WDelay(500)
                        FillCircle(x,y,r)
                        hit := 1
                        break break
                        }
                    }
                }
            }
        DrawCircle(x,y,r)
        if \hit then r *:= .9 else r *:= 1.10
        x := ?Width; y := ?Height
        }
end