Add from Search or Add New Record within a Form

I have an item-type named 'Dept' and a property within 'Dept' called 'contact' which is a datatype item. When I insert 'contact' into my 'Dept' FORM, it only gives me the ability to add a record from the search. How can I also have the ability to ADD a NEW record from the 'contact' field.

Thanks

Dominic