Problem :
What triggers user login name if we want use in the Personalization Form ?
Exp: if login as SALES_ADM, they can't click Action
Solution
It is easier to use a custom profile. If having more than one user you want to exclude from function you would not end up with a massive list of user_ids in your personalization
If you create your custom profile call it say XX_DISABLE_ACTION which you would create as Y(es) or N(o). Set it globally to No and Yes for the users you want to lock out.
Then have
FND_PROFILE.VALUE('XX_DISABLE_