you do not need....
You do not need old company\'s notice of approval. You need the approval of current company and most importantly a letter from the current employer and most recent paystubs (atleast 2 to 3) in addition to copies of I-129 application with supplement, laca and I-129 W. If your education is not from U.S. School, you need to carry a copy of your evaluation report also in addition to original degree certificat and transcripts.
Basically, I-797 (i.e. the notice of approval) top portion is an employer document. That is the reason why they do not ask for such document of the previous company. However, it becomes a mandatory document from the present company and you have to carry the original approval notice of the current employer.