[Zope] problems creating a Contents management tab

i have a python product and i am trying to create a contents management tab. the product inherits from ObjectManager and the module imports ObjectManager from OFS.ObjectManager these lines of code do not work... manage_options = ({'label':'Contents','action':'manage_main'}, {'label':'Edit','action':'editForm'}, {'label':'View','action':''},)+RoleManager.manage_options\ +Item.manage_options manage_main = ObjectManager.manage_main i get this error: Error Type: AttributeError Error Value: 'string' object has no attribute 'has_key' can anyone help? thank you in advance. -bob