Warning: Undefined variable $document in /volume1/web/rickykung.com/cms/alpha/2011-01/20110131/ajax/popUp.php on line 2

Fatal error: Uncaught Error: Call to a member function appendChild() on null in /volume1/web/rickykung.com/cms/alpha/2011-01/20110131/ajax/popUp.php:2
Stack trace:
#0 {main}
  thrown in /volume1/web/rickykung.com/cms/alpha/2011-01/20110131/ajax/popUp.php on line 2