Php文件URL确实显示主页而不是Php文件

px.multiscreensite.com的代理URL通过存储在px.multiscreensite.com/index.php的php文件工作，但是当试图通过查看php文件来调查代码时，它只显示与主页完全相同的代码。为什么我不能查看php文件，是不是有什么花招。如果你无法查看网页，因为它被阻止了，毕竟它是一个代理，这里是网页代码:

<div id="container">
  <h1 id="title">PHProxy</h1>
  <ul id="navigation">
    <li><a href="https://px.multiscreensite.com/">URL Form</a></li>
    <li><a href="javascript:alert('cookie managment has not been implemented yet')">Manage Cookies</a></li>
  </ul>
  <form method="post" action="https://px.multiscreensite.com/index.php">
    <ul id="form">
      <li id="address_bar"><label>Web Address <input id="address_box" type="text" name="url" value="" onfocus="this.select()" /></label> <input id="go" type="submit" value="Go" /></li>
      <li class="option"><label><input type="checkbox" name="hl[remove_scripts]" />Remove client-side scripting (i.e JavaScript)</label></li>
<li class="option"><label><input type="checkbox" name="hl[strip_meta]" />Strip meta information tags from pages</label></li>
    </ul>
  </form>
  <!-- The least you could do is leave this link back as it is. This software is provided for free and I ask nothing in return except that you leave this link intact
   You're more likely to recieve support should you require some if I see a link back in your installation than if not -->
  <div id="footer"><a href="http://whitefyre.com/poxy/">PHProxy</a> 0.5b2</div>
</div>
</body>
</html>