Alert for DFF Fields

Hi

I have a requirement to Trigger an alert in case if some DFF Fields(Attribute40,41 and 42) at Header Level are NULL on the Service Contract Form during submitting the "Check QA" Process under Actions Tab.

Is there a way to Achieve this through Form Personalization? Also is there a Trigger Object Name for the "Check QA" available?

If this is not possible through Form Personalization, Please guide me the detail process to do it through Custom.pll way or provide any References.