Combo Box Adding Button to edit list items

I have a form which is designed to enter information about jobs we have
completed. It has 3 combo boxes for different types of contacts that are
pulled from different tables. I want the user to be able to select from the
list or add a new contact. I know they can right click on the drop down
arrow for the combo box and select "Edit List Items" but I really would like
to add a button next to each combo box that gives them that option. I have
tried creating a button next to it that opens up the form for the contact and
then a button on that newly opened form to save and close. However, the new
contact does not show up in the original job form unless I close out of that
and reopen it.