I have a simple program which is able to change the background color after clicking a button, but it does not work

public class ChangeBackgroundActivity extends Activity {
/** Called when the activity is first created. */
    Button blueButton;
    LinearLayout myLO;
    @Override
   public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        myLO=(LinearLayout)findViewById(R.layout.main);
        blueButton=(Button)findViewById(R.id.button1);
        blueButton.setOnClickListener(new OnClickListener() {

            public void onClick(View arg0) {
            // TODO Auto-generated method stub
            myLO.setBackgroundColor(0x0000FF); //blue color code #0000FF    
        }
    });
    }
}