Hey There,
Let me be the first to introduce you to Database Normalization:
http://bytes.com/topic/access/insigh...ble-structures
The above is one of the Links NeoPa was referring to. In short it will explain to you why you should move the data you have in your three separate Shift Tables into one Table and include a column to record which shift the record belongs to. This will provide you a much easier way to write your Forms, Queries and Reports since you will only have to write them once instead of three times.
Not only that, the question that you are asking about will go away as you will only be adding data to one Table. The question will most likely be replaced by, how do I Filter the Form to only show one shift?