[Forums] How to give confirm message before update operation?

Good Afternoon people,

I am importing XML contents into database. Before import, I have applied the check whether record is already present or not. 

If record is present I am updating it.

But before update happens, I want to take permission of user. If user clicks "Yes", it should update else it shouldn't update and come out.

How can I give confirm message inside action?

Thanks and Regards,
Suraj Borade