# Set control A to a specific value if control B is ever changed?

I've had trouble with this and issues similar to this in the past, where I need to track when a controlled variable is changed. Basically I have two Sliders (call them A and B) and whenever B is changed with its slider, A should be reset to some value, let's say it should be reset to 10 anytime B is changed.

In some way, shape, or form, I have never been able to come up with a reasonable solution to problems like these.

Manipulate[{a, b},