Get CurrentUser in calculation precondition

Hi,

I need to let only 'created by' user and 'Raise User' to close an incident

I create a precondition with calculation ype to test if created by ( or raise user) is the current user

My code is :

import System

static def GetAttributeValue(Incident):

Value = 'False'

if Incident.RaiseUser== '$CurrentUser$' or Incident.CreationUser =='$CurrentUser$': Value = 'True'

return Value

This is not working for me.

How can I solve this.What is wrong?

Please see attached file to have an idea of my resolution process part

Thanks

Regards