He has AX 2012 tags, so pasting D365fF&O details is not going to be helpful.
SAM: why are you trying to implement something, which is already there. AX saves information which you have entered in a table/field-bound control on a form, if:
- you press the Save button on the toolbar (if you have enabled those)
- you press Control + S
- you navigate away from the record
- you close the form with the Window X button, or Close button
Implementing a save functionality for a button does not sound like Best practice for me at all.