[Zope-dev] Question about Labels

Hi, I have a Product with a Label called Foo. Now what can i do, that when anyone clicked on the tab Foo first the function bar() is called and after that the HTML-File is displayed. as manage_options =({'label':'Foo', 'action':'manage_propertiesForm'},) def bar(self): do anything before displaying the HTMLFile def manage_propertiesForm(self,REQUEST): """ doc string """ self.bar() return HTMLFile('edit_NetzwerkForm', globals())