Also the onPause() in Android is part of the Android app lifecycle and shouldn't be your issue. (i.e. what happens when you minimize the app)
http://developer.android.com/training/basics/activity-lifecycle/index.html
I think it's because you need an onClickListener for the Button.
This is a pretty good example of how to use a button correctly.
http://stackoverflow.com/questions/3320115/android-onclicklistener-identify-a-button