title: Android main activity destroy(finish) automatically
body: <p>In my App there is three activities:  A, B, and C. Activity A is the main activity. </p>
  
  <p>When I start Activity B from A using <code>Intent</code>, A is automatically destroyed. However, I am not finished with A when I start B. Then, when I press the back button in the device the A is started using <code>onCreate</code> and I've lost all my data since I am not using an <code>Intent</code> to go back.</p>
  
  <p>The same happens when opening C from B.</p>
  
  <pre><code>button.setOnClickListener(new OnClickListener() {
  
              @Override
              public void onClick(View v) {
                  // TODO Auto-generated method stub
                  startActivity(new Intent(ActivityA.this,
                          ActivityB.class));
              }
          });
  </code></pre>
  
  <p>What's going on? How do I fix this?</p>