Android Question Put a button and msgbox on preference activity

hi its possible put a button on preference activity?
i want to put a button with text = "Save and Exit"
i see in many apps this i think this is possible on b4a but dont know how xD

and 2° questions its possible add msgbox when you select a item on preference activity?
for exemple i make a language selection

if user select portugues show msgbox("Do you really want this?") yes or no
its possible? *-*

thx to all