H-4 Visa:
Question: Can you please let me know if I can send my wife and son to India for a few months and return to US without stamping with new petition? Their H4 visa on passport is valid till Jan 2013 but with my previous petition.
Answer: Yes you can. The H-4 visa is valid until expiration as long as you are in H-1B status. The H-4 is not tied to your current employer in the same way as your H-1B status.