defined object variable

git-svn-id: https://svn.muze.nl/svn/ariadne-php5/trunk@6423 7882d7ee-46e0-0310-a255-a28a61b628e4
use isset for checking instead of evaluating

git-svn-id: https://svn.muze.nl/svn/ariadne-php5/trunk@6424 7882d7ee-46e0-0310-a255-a28a61b628e4
define used variables

git-svn-id: https://svn.muze.nl/svn/ariadne-php5/trunk@6425 7882d7ee-46e0-0310-a255-a28a61b628e4