Windows Calculation to make a field mandatory

Hello -

I'm trying to make a field mandatory when an Int32 attribute has a certain value and I'm having no luck.  It says my syntax is valid but the field never becomes mandatory.

Can someone take a look and tell me what's missing?  Thanks

import System

static def GetAttributeValue(Resolution):

          Value = false

          if Resolution._PrivilegedAccess != null and Resolution._PrivilegedAccess == "Yes":

                    Value = true

return String.Format(":SetMandatory(Resolution._PrivilegeJustification, {0});",Value)