I have one button (`buttton1`) in the first activity and the second activity has a textview 
(`textView1`). This is the code that I wrote:

```
public void buttton1 (View v){

Intent buttton1 = new Intent (MainActivity.this, Back.class);

startActivity(buttton1);

TextView textView = (TextView)findViewById(R.id.textView1);

textView.setText("Hello");

finish();

}

```

When I run the application and when I click on the button, it force-closes.
So please help me where is the fault?