I am pulling information from three different tables into a new table.

Tables:
Job_Master
Vendor_Master
Insurance_Master
Job_Detail

Example: On my form I have a combo boxes that I use for searching for the job_number from my Job_Master table, Vendor_Abbrev from the Vendor_Master table and the Insurance_number from the Insurance_Master table. I then want to save this newly formed key and these fields into the Job_Detail table.

How can this be done?

In order for you to accomplish you have to create a query that will join all tables, select * from from the table and add the additonal field needed.

TBL1 TBL2
PR_NUM ITEM_NUM

Product_num:[PR_NUM] & [ITEM_NUM]

Remember to base your combo box on the query.