Add a signature to a .pdf document

I need to have a signature added to two .pdf documents. I have the documents and a .tif of the signature data. ## Deliverables The attached zip file contains the two .pdf documents to be updated with the signature. There is a 3rd .pdf doc. with a sample signature in it. The signature graphic is in the zip file as both .jpg & .gif format. You can use either. The area where the signature is to be added is the at the bottom left on page one of each form where it has a title "Signature of employer or authorized officer". On the French form the title is " Signature d'employeur ou d'un mandataire autorise".