[Zope] show filesize in LocalFS

Hi all, When using the following statements I receive the message "Error Type: NameError Error Value: global name 'get_size' is not defined". <dtml-in "admin.fileIds()"> <dtml-var sequence-item> <dtml-var "bobobase_modification_time()"> <dtml-var "get_size()"> </dtml-in> What did I do wrong ? How can I display the filesize of the current file ? Regards, Michael