title: PHP:mkdir() can't create folder
body: <p>I know there are similar topics,but when I tried using them, I still got the same error.
  The problem is this:</p>
  
  <pre><code>Warning: mkdir() [function.mkdir]: No such file or directory in /home/... on line 30
  </code></pre>
  
  <p>I got this code:</p>
  
  <pre><code>$id = mysql_insert_id();
  mkdir("memberFiles/$id", 0755);
  </code></pre>
  
  <p>What's the problem?I already have memberFiles folder.</p>