How would I create a sub-form that is not visible with out command (command button, etc) and inputs the unique identifier. For example, when I track chemotherapy, most often patients are given multiple courses. I would like to be able to have a command button that would "add a new course" the sub-form would pop up and the medical record number of the active patient record in the parent table would be the default for the medical record number in the treatment table.

Any help will be greatly appreciated!

OnOpen
subform.visible = false

OnEvent
subform.visible = true

Thanks for the suggestion but because I am a newbie, is there a way to handle this throught the properties? ie pop-up=yes modal=yes? Code for me is a little scary right now!

If I link by medical record number, enter the Medcal record number on the parent from and use a command button to open the child form (having set to find specific data to look-up) If I don't use the linked field in the child form, will the new records be given the unique identifier of the active record in the parents form?