title: HTML5 Email input pattern attribute
body: <p>I’m trying to make a html5 form that contains one email input, one check box input, and one submit input.
  I'm trying to use the pattern attribute for the email input but I don't know what to place in this attribute. I do know that I'm supposed to use a regular expression that must match the JavaScript Pattern production but I don't know how to do this.</p>
  <p>What I'm trying to get this attribute to do is to check to make sure that the email contains one @ and at least one or more dot and if possible check to see if the address after the @ is a real address. If I can't do this through this attribute then I'll consider using JavaScript but for checking for one @ and one or more dot I do want to use the pattern attribute for sure.</p>
  <p>The pattern attribute needs to check for:</p>
  <ol>
  <li>Only one @</li>
  <li>One or more dot</li>
  <li>And if possible check to see if the address after the @ is a valid address</li>
  </ol>
  <p>An alternative to this one is to use a JavaScript but for all the other conditions I do not want to use a JavaScript.</p>