using preg_match to check email domain
<p>How can I modify the preg_match function below to allow all email addresses ending with harvard.edu email addresses, instead of only those with @college.harvard.edu?</p>

<pre><code>if(!preg_match("/@college\.harvard\.edu$/", $_POST["username"]))
    {
        apologize("You must provide a Harvard email to register.");
    }  
</code></pre>
