Avoid calling adverse document methods with jQuery.event.trigger

Calling jQuery.event.trigger('open') or jQuery.event.trigger('write')
will result in calling document.open() or document.write() as jQuery's
trigger will see if the method is available on the element (in this
case, the document). Calling either open() or write() without arguments
will simply empty the current document, which is an easy way to shoot
your foot off.

Hat tip to Joe Lencioni for finding this quirk.

Related ticket:
  http://bugs.jquery.com/ticket/13638