Application crashes on button click

Question

Have problem that when I press button application crashes. Crash text package com.leftas.vidurkioskaiciavimas;

 24367-24367/com.leftas.vidurkioskaiciavimas E/An         


        

Answer 1

findviewbyid and mUserOutput.setOnClickListener(this); required .

also implement onLCicklistener like: public class MainActivity extends Activity implements OnClickListener{