Open Form Not Adding Record And Use An Add Button On Form

I have a database with three tables

table 1 (form1)
reference (PK) auto number

table 2 (form2)
Reference (fK)
workbook reference (PK) auto number

Table 3 (sub form within in form2)
Reference (FK)
workbook reference (fK)
data Reference (pk) auto number

Each table is a form that is linked via the keys. On form 1 i have a button that is to open the form2, which it does but every time i open the form a new record is added. Why and how do i prevent this.

Then what i want to do is add a button for a new form on table 2 form but use the same reference as the record as presently displayed. How do i add new record using the same Reference but new workbook Reference?

Thanks is advance