title: Extra content at the end of the document PHP and XML
body: <p>I having a strange problem when I'm trying to produce an XML file with PHP. The problems is that, a strange question mark appears at the end of the source code. And I get the error: "Extra content at the end of the document" </p>
  
  <p>I'm running this script:</p>
  
  <pre><code>&lt;?php
  header("Content-Type: application/xml");
  echo "&lt;?xml version=\"1.0\"?&gt;";
  ?&gt;
  
  &lt;Module&gt;
        &lt;ModulePrefs title="Ngram Extractor"
          author="interedition team"
         description="Ngram Extractor"
          scrolling="true"/&gt;
          &lt;Content type="html"&gt;
          Test
          &lt;/Content&gt;
  &lt;/Module&gt;​
  </code></pre>
  
  <p>When I open this is a browser, I get the state error and the source code looks like this. Notice the strange question mark at the end.</p>
  
  <pre><code> &lt;?xml version="1.0"?&gt;
  &lt;Module&gt;
        &lt;ModulePrefs title="Ngram Extractor"
          author="interedition team"
         description="Ngram Extractor"
          scrolling="true"/&gt;
          &lt;Content type="html"&gt;
          Test
          &lt;/Content&gt;
  &lt;/Module&gt;?
  </code></pre>
  
  <p>Please help.</p>