I have a combo box in a subform that user can either select or not select the value from the combo box. I can get the value of the combo box if user made a selection. However I can not detect if user did not make any selection from the combo box, he just tab over to the next field. What I would like to do is that when user tab over the combo box field (first field on subform,order details) it means that user want to finish this order and jump to the main form for a new customer. Can any one help?
TIA
Joe

Presumeably if the user hasn't made a selection from the combo box it will be null,and you can then use Iif IsNull