PHP - check to see if input name start with specific name
<p>I have several input fields for uploading files:</p>

<pre><code>&lt;input type=file name=logo /&gt;
&lt;input type=file name=userfile /&gt;
&lt;input type=file name=userfile1 /&gt;
.
.
.
&lt;input type=file name=top /&gt;
&lt;input type=file name=bottom /&gt;
</code></pre>

<p>Every file needs to be treated in some different way. How can I check if <code>$_FILES</code> starts, for example, with <strong>userfile</strong>?</p>
