title: RelativeLayout's layout_above gives "No resource found" error
body: <pre><code>&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent" &gt;
    &lt;ListView
        android:layout_above="@id/btn_4"    &lt;-- this line error: No resource found
        android:layout_width="match_parent"
        android:layout_height="200dp" /&gt;
    &lt;Button android:id="@+id/btn_4"         &lt;-- I declare the id here
        android:layout_alignParentBottom="true"
        android:layout_height="wrap_content"
        android:layout_width="match_parent" /&gt;
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>Any suggestions?</p>