OnPaint Event

[C# Programming]

Hi everybody

I have a panel in my form, I used backgraound image for my panel.
In the Panel OnPaint event body, I draw ellipse with various position and dimension on each times.
So I use a timer, On the OnTimer event I ******* panel for clearing previous ellipse and draw new ellipse with new parameters.

when form *******ed a bit jumping occurred in my background image, since I use mentioned operation every second, these jumping annoy the user.
I want to know how can disappear these jumping, Maybe for clearing prior ellipse use another method instead ******* or invalidate.

Best Regards,
Reza Shojaee