set the date-field to auto-enter (date) and the user-field to auto-enter (account name, what ever fits best). These settings are under manage database, field, options
You don't need a trigger. You can do this with an auto-enter calculation. Go to File > Manage Database. Select the Director Date field and click "Options". Click the "Auto-Enter" tab (if not already selected):
Click the "Specify" button next to "Calculated value". Enter this calculation in the resulting dialog:
Case ( not IsEmpty ( Director comments ) ; Get ( CurrentDate ))
Leave the "Do not replace" checkbox checked.
You can perform a similar operation for User. Just substitute Get ( AccountName ) for Get ( CurrentDate ).