title: Hitting "enter" does not post form in IE8
body: <p>I'm using PHP to pass a login form when required, and here is the code:</p>
  
  <pre><code>$htmlForm = '&lt;form id="frmlogin"&gt;'.'&lt;label&gt;';
  switch(LOGIN_METHOD)
  {
      case 'both':
          $htmlForm .= $ACL_LANG['USERNAME'].'/'.$ACL_LANG['EMAIL'];
          break;
      case 'email':
          $htmlForm .= $ACL_LANG['EMAIL'];
          break;
      default:
          $htmlForm .= $ACL_LANG['USERNAME'];
          break;
  }                       
  
  $htmlForm .= ':&lt;/label&gt;'.
               '&lt;input type="text" name="u" id="u" class="textfield" /&gt;'.
               '&lt;label&gt;'.$ACL_LANG['PASSWORD'].'&lt;/label&gt;'.
               '&lt;input type="password" name="p" id="p" class="textfield" /&gt;'.
               '&lt;center&gt;&lt;input type="submit" name="btn" id="btn" class="buttonfield" value="Sign in to extranet" /&gt;&lt;/center&gt;'.
               '&lt;/form&gt;';
  
  return $htmlForm;
  </code></pre>
  
  <p>The problem is, is that when the user hits enter in IE8, the form does not submit, and the user is forced to hit the submit button. </p>
  
  <p>How do I rectify this?</p>