Calculation to get User director hierarchy

Hi,

In active directory, i have basic information for a user : name, last name, function and Manager

I am looking to get the director of user from the Manager information

So, I need to make a calculation on a newx attribute created under user Object named 'Director' like this

import System

static def GetAttributeValue(User):

N=1

while N>=1:

    if User._JobTitle == 'Director':

        return User

    else

      User=User.User.Manager

      N=N+1

Can some one tell me please what is wrong with my calculation

Thanks very much