Thank you for Zope. Yea! It is a thing of beauty! I have created a simple file repository with an explorer-style interface, search form and access control. It's like a much-simplified version of the management UI, whose code I have been staring at. This has helped a lot, as have the mailing list archives. My search form uses an external method which is similar to FindSupport.PrincipiaFind(). It has one problem - it lists files for which the user does not have view permission. The tree tag handles this well and I want to add a similar validate() check to my find method, but I cannot find the right magic! I am confused about the arguments and have found debugging difficult. Eg I cannot step into the external method. Any tips would be most welcome.. -Simon