Adding classes with PHP echo, not replacing them
<p>First of all, I know this is simple but I'm not a PHP developer by trade so I apologize if this is dumb for everyone. That being said, I've spent the last 3 hrs searching and can't find a way to do this without re-inventing my wheel so to speak. I use a simple command to mark the navigation on websites when the page is "current". </p>

<pre><code>&lt;li&gt;&lt;a &lt;?php if (strpos($_SERVER['PHP_SELF'], 'page')) echo 'class="current"';?&gt; href="page.php" class="tp"&gt;Page&lt;/a&gt;&lt;/li&gt;
</code></pre>

<p>Works great in most cases. However in this case, I need to concatenate the class string, not overwrite it with current. I've tried</p>

<pre><code>...echo'class=" "."current".' 
</code></pre>

<p>and several variations and can't get it to simply add the class not overwrite it. Thank you</p>
