It seems that your script is not in the same directory as Serendipity. So you should do a "chdir($serendipity_directory)" first, because Serendipity tries to load its configuration file and seems to fail.
# Garvin Hicking (s9y Developer)
# Did I help you? Consider making me happy: http://wishes.garv.in/
# or use my PayPal account "paypal {at} supergarv (dot) de"
# My "other" hobby: http://flickr.garv.in/