Hello, I've created a zclass to manage a list of tasks to be done with some properties called todo_title, todo_priority, todo_expiry,... The propertysheet is called 'todo_info', the product 'ToDoProduct' and the zclass 'todo' Each instance is created in a folder called 'todos' with names like 'a982706331', 'a456812195',... I put the instance id in a variable called 'todo_id' I'm trying to change zclass instance properties. I followed the Zope Developer's Guide : <dtml-call "a982706331.manage_changeProperties({'todo_title':'Do this'})"> but nothing changes (no error messages). I tried a lot of different things like : <dtml-with "todo.createInObjectManager(REQUEST['todo_id'],REQUEST)"> <dtml-call expr="propertysheets.todo_info.manage_editProperties({'todo_title':'Do that'})"> </dtml-with> or <dtml-with todo_id> <dtml-call "manage_editProperties({'todo_title':'Do this'})"> </dtml-with> or <dtml-with todo_id> <dtml-call "manage_changeProperties({'todo_title':'Do that'})"> </dtml-with> Could someone help me fix the problem ? Also : what's the difference between 'manage_editProperties' and 'manage_changeProperties' ? Thanks, Olivier Laurent.