So I have a Droid 2 Global because it has SIM card capabilities. I called Verizon to allow international roaming. Then I got the unlock code for my phone. Next I put a new-bought SIM card from China Mobile into my Verizon Droid 2 Global.
However, when someone calls my China Mobile phone number, my phone does not react. The caller hears a prerecorded message that the China Mobile phone number is incorrect or not connected.
When I call with my Droid 2 Global with the China Mobile SIM card inside, the receiving person sees my Verizon phone number.
My question is: How do I get my Droid 2 Global to recognize and use my China Mobile SIM card?
I don't want it to use my Verizon phone number while I am overseas. I like my Verizon service in the U.S., and I plan to return to it. I just thought the idea of a global phone with a SIM card was to be able to travel to other countries and use another SIM card if need be, and the sales representatives at my local Verizon store sold me this idea of international usage. Other users seem to have no problem. Please inform me of how it works 
Thank you!