> Would that be in LostFocus or KeyPress or ?? (I am asking to make sure, instead of trying and findout later it isn't the right settings). While at that, would I use CHR(13) or INKEY(13) (as well CHR(27) to go back as is with Esc key)?

The best way to understand form events is to play around with them.
1) Open your form
2) Start the debugger From the TOOLS menu, click DEBUGGER
3) Select TOOLS the EVENT TRACKING, then click TURN EVENT TRACKING ON
4) Click the OK button
5) Switch back to VFP then run your form and try the actions you were asking about. You can see which events fire under which circumstances