Animate a circle loop

[uscuba2]

I need some help. I want to have a circle arching/dropping but I do not get loop that I need to use. How do I do this?
{
AppWindow Win;

Setup(Win, 0, 0, 600, 600);
SetText(Win, "Ball Drop");

SetDrawColor(Win, 0.0, 0.0, 0.0);
Circle(Win, 175, 175, 15);

Sleep (100);

SetDrawColor(Win, 1.0, 1.0, 1.0);
Circle(Win, 175, 175, 15);

system ("Pause");

}

[Zaita]

OpenGL would be a quick easy way to do this. www.opengl.org