PHP Detect if any URL variables have been set
<p>I have a webpage to which any amount of URL varibales could be set.. examples:</p>

<ul>
<li>index.php?source=lol   </li>
<li>index.php?source=lol&amp;sub=haha</li>
<li>index.php?aff=123</li>
<li>index.php?keyword=pizza</li>
</ul>

<p>I want a way that I can detect that any url variable has been set, if a url variable has been set I want to print something on the page. Any ideas? I couldn't find anything on Google about this.</p>
