title: add onclick listener to predefined button?
body: <p>I've got the following button in my xml layout file...</p>
  
  <pre><code>&lt;Button
      android:layout_width="150dip"
      android:id="@+id/button1"
      android:layout_height="50dip"
      android:text="@string/login"
      android:layout_marginRight="10dip"&gt;
  &lt;/Button&gt;
  </code></pre>
  
  <p>I'd like to programmatically add an <code>onclick()</code> listener in it's Java file. How would I do this?</p>