NI-Vision IMAQ Find Circular Edge

Hi,

I got a some proble with the fonction find a Circular Edge of LabView Vision.  The problem is when the fonction found my circle he put a red circle, This is good ! but when I move the object for try to track the point, all the old red circle won't disaper.

After i while its pretty messy in my interface.

I got a image of the problem.

I want to know how to erase all the circle a each iteration.

Thank you