Try this if you've not already:
Find your Forms 'After update', event procedure and enter:
msgbox "your msg",48,"I've entered something"
after new record entered and you go to next record this msg will appear
this will also appear if you amend any record on form so maybe not as required
you change stuff in quotation marks"" to suit
nb: 48 = exclamation mark icon, others are availabe, VB standard values