title: PHP function use variable from outside
body: <pre><code>function parts($part) { 
      $structure = 'http://' . $site_url . 'content/'; 
      echo($tructure . $part . '.php'); 
  }
  </code></pre>
  
  <p>This function uses a variable <code>$site_url</code> that was defined at the top of this page, but this variable is not being passed into the function. </p>
  
  <p>How do we get it to return in the function?</p>