My earlier H-1B stamp is no longer valid; thus, I applied for my H1b extension. My H1b extension has been approved, which is good until 2009 according to the I-94 attached at the bottom. My concern is that if I go to Mexico how will I re-enter the US since my earlier H1b stamp is no longer valid? Do I need to go to the US embassy and appear before a US consul in Mexico to have my passport stamped and re-enter the US? Is there a risk if I choose to do this?