title: file_get_contents HTTP request failed
body: <p>I written simple php code to get some url content but it dosn't work
  it return this error</p>
  
  <blockquote>
    <p>file_get_contents(<a href="http://www.nature.com/nature/journal/v508/n7496/full/nature13001.html" rel="nofollow">http://www.nature.com/nature/journal/v508/n7496/full/nature13001.html</a>) [function.file-get-contents]: failed to open stream: HTTP request failed! HTTP/1.0 401 Unauthorized</p>
  </blockquote>
  
  <p>here is my code. please help me.tnx</p>
  
  <pre><code>$content=file_get_contents('http://www.nature.com/nature/journal/v508/n7496/full/nature13001.html');
  echo $content;
  </code></pre>