Break processing

I have a menu that fades in and out the opacity property. When the user MousesOver a link a menu fades in, and when the user MousesOut the menu fades out. The fading process uses setTimeout().

Both fade-in and fade-out work properly when isolated of each other. When the user MousesOver, then MousesOut before the menu fades in entirely the fading processes clash and freeze.

Is there any way to break all or any one current JS processes on a page? If it is possible then I can break the fade-in process before the fade-out process to solve the problem.

Also, can you suggest, if possible, a better way to solve it?

Thanks.