[Zope] User acces to this()

Hi everybody, hope someone can help me. I have a mySQLuserfolder with a role Called Student. I now only want to show a piece of the page if the user is logged in as a student so I have this in my DTML Method: <dtml-if "AUTHENTICATED_USER.hasRole(this(), ['Student'])"> But If I log in having a student role I get a unauthorized exception saying I´m now authorized to access "this". Does anyone have a hint to help me on this? Do I need to set a security role or something? Hope someone can help me on this one. Greetz, James