Conditional pause/resume

This is probably posted somewhere but I couldn't find it.

When the user is filling out a form, there may be a need to add a new item or category in a subform. An "add new item" button is next to the field, so by clicking on it, the user is taken to the item/category/etc. db, the script is paused, to add the item, then returned to previous db by pressing enter on the number pad (with "go to last field" in script to end up in the same place). My goal is for a "continue" button to appear on the layout where the new item/category/etc. is being added so that the user does not have to always remember to press the "enter" key on the number key, and not the regular enter key.

The "continue" button should be conditional and NOT appear if the user enters the subform db directly to add, delete, or modify. The condition would be that the "continue" button appears only when adding a record that is needed to finish filling out the main form.

Thanks in advance for the help.