(sorry for asking this question again. i do need some help... ^_^) my table schema: create sequence sessions_session_seq; create tale sessions ( session varchar(255), primary key (session) ); create table session_data ( session varchar(255), name varchar(255), value varchar(255) ); i have changed sqlSessionCreate SQL method: insert into sessions ( session ) value ( nextval('sessions_session_seq') :: varchar ) i wrote some tests in dtml method: <dtml-comment> things work </dtml-comment> <dtml-call Session> <dtml-call "SESSION.set('attribute1', formField1'"> <dtml-call "SESSION['attribute1']"> <dtml-in "SESSION.keys()"> <dtml-var sequence-item> = "<dtml-var "SESSION[_['sequence-item']]">"<br> </dtml-in> <dtml-comment> things don't work <dtml-call "SESSION.clear()"> </dtml-comment> if i uncommented "things don't work" block, i will get traceback: Traceback (innermost last): File /home3/local/src/Zope-2.1.5-src/lib/python/ZPublisher/Publish.py, line 214, in publish_module File /home3/local/src/Zope-2.1.5-src/lib/python/ZPublisher/Publish.py, line 179, in publish File /home3/local/src/Zope-2.1.5-src/lib/python/Zope/__init__.py, line 202, in zpublisher_exception_hook (Object: ElementWithAttributes) File /home3/local/src/Zope-2.1.5-src/lib/python/ZPublisher/Publish.py, line 165, in publish File /home3/local/src/Zope-2.1.5-src/lib/python/ZPublisher/mapply.py, line 160, in mapply (Object: sessiontest) File /home3/local/src/Zope-2.1.5-src/lib/python/ZPublisher/Publish.py, line 102, in call_object (Object: sessiontest) File /home3/local/src/Zope-2.1.5-src/lib/python/OFS/DTMLMethod.py, line 150, in __call__ (Object: sessiontest) File /home3/local/src/Zope-2.1.5-src/lib/python/DocumentTemplate/DT_String.py, line 502, in __call__ (Object: sessiontest) File /home3/local/src/Zope-2.1.5-src/lib/python/DocumentTemplate/DT_Util.py, line 335, in eval (Object: SESSION.clear()) (Info: SESSION) File <string>, line 0, in ? File /usr/local/src/Zope-2.1.6-src/lib/python/Products/SQLSession/SQLSession.py, line 172, in clear File /home3/local/src/Zope-2.1.6-src/lib/python/Shared/DC/ZRDB/DA.py, line 408, in __call__ (Object: sqlDeleteValue) File /home3/local/src/Zope-2.1.5-src/lib/python/Shared/DC/ZRDB/Aqueduct.py, line 186, in _argdata (Object: sqlDeleteValue) Bad Request: (see above) -- 'Life is like boxes of chocolate, Forrest. You never know what you're gonna get.' -- Forrest Gump (1994) Lo Chung-Chang (shortie) shortie@ms14.hinet.net http://shortie.vbc.com.tw/ ICQ#27118251 Kaohsiung.Taiwan.Roc.Earth.Solar.Galaxy.Universe