title: Regex - how can I make my expression case insensitive?
body: <p>Here's the regex I'm using:</p>
  
  <pre><code>.*?\@(?!yahoo|gmail|hotmail).*
  </code></pre>
  
  <p>Basically I'm trying to get all non-yahoo/gmail/hotmail email addresses. The above works, however if someone types "ISHOUTATEVERYONE@YAHOO.COM" then it won't match.</p>
  
  <p>I've tried searching around for an answer but nothing working. Is this possible?</p>
  
  <p>I'm trying to use this on a HTML5 Input Pattern attribute:</p>
  
  <p><code>&lt;input type="email" pattern=".*?\@(?!yahoo|gmail|hotmail).*" title="Email Address (no yahoo, gmail or hotmail)" id="emailaddress" name="emailaddress" required=""&gt;</code></p>