Touch screen and object conflicts

Hi, I have a very noob question about touch controls. and I think its very common case:

I have a "Is in touch" event that when player touch anywhere on screen it do A.

and I also have a button on screen. when player touch that button, I want player do B.

Now player will do both A and B if I touch the button. how do I fix this?

In your event to detect "is in touch", you should create an invert condition "is touching object", with the object being the button.