quickform: creating object with new =& or new =

Hi all, I am wondering when creating a new instance of a QuickForm I have seen two ways of doing this in the sample documents. like... $form =& new HTML_QuickForm('testing', 'post'); and like... $form = new HTML_QuickForm('testing', 'post'); what is the difference and which is better to use? Also, (related?) when creating a default for a form item I have seen this done two ways: like this... $form->setDefaults(array('fuseaction' => $XFA['XFA_FundingAnnouncements'])); and like... $defaultValues['fuseaction'] = '$XFA['XFA_FundingAnnouncements']'; What is the difference with these? Thanks for any help. - Charles