I am not understanding what the Commit Data is for under Default Button and Button 2. I have Filemaker Pro 12. It seems that when I have Default Button set for Add New Record it does that whether Commit Data is checked or not. So I am confused for the purpose of this field.
The Custom Dialog box can be used to input data. You can specify input fields, so to have the data committed to the database you would select commit data. You would add commit data so the input fields update as soon as the button is clicked.