Unanswered: Fairly simple task - unsure of best way to achieve it
I have a subform which includes a reference field whose number is usually automatically generated through an update query (but can be manually entered from this subform). Once a number has already been entered, I would like the field to be able to be changed but only after the user is warned and clicks 'yes' on a message box.
If the user clicks 'no' the field should retain the old value and the next control on the subform should get the focus.
Any ideas on how best to achieve this?
Specifically, on what event should I run my code?
OnKeyPress, OnChange,BeforeUpdate,AfterUpdate or otherwise?