Need a snake identified

[Sunrunner]

Ok I have a friend who was in South Vietnam and he was asking me about a snake that was found there they called it a "Two Step snake" because it was so deadly, he says it was grey/silver and maxed out at 12 inches and it was found in the jungles I am at a loss so any help naming this snake for him would be appricated.
Thanks

[Hamster of Borg]

http://www.manbir-online.com/questions/twostep.htm

[Sunrunner]

TY but it does not specify the peticular one i am looking for it just says there were many ones does anyone know this peticular one?
And ty btw it is a good site for info