Delete output parts
<p>I want to be able to delete some output buffer parts. So that considering this code:</p>

<pre><code>function over_all($string) {
    if (OVER_ALL_ENABLED) { 

        # Stop output buffer
        # Clean output buffer

        echo $string;

        # Restart output buffer
    }
}

ob_start();

echo 'This is phrase 1&lt;br&gt;';
over_all('I don\'t want to see Phrase 1&lt;br&gt;');
echo 'This is phrase 2';
over_all('I don\'t want to see Phrase 2');
</code></pre>

<p>If I set <code>OVER_ALL_ENABLED</code> to true it will print:</p>

<blockquote>
  <p>I don't want to see Phrase 1<br>
  I don't want to see Phrase 2</p>
</blockquote>

<p>else:</p>

<blockquote>
  <p>This is phrase 1<br>
  This is phrase 2</p>
</blockquote>

<p>Could you replace comments with correct PHP functions?</p>
