USA Visa staple (Doha)

Hii guys,

I got my USA B1/B2 Visa stapled on my passport in August'2015.

Now the photograph on that passport got a little moisture and defaced a bit (I have traveled twice after that on same passport). Though it has my year by year Qatar visa stapled to it with same photograph but to be cautious I wish to change my passport from Indian Embassy mentioning it as damaged.

I wish to know what will happen to US visa in case a new passport with new number is issued to me?? Do I need to apply US visa again or producing old passport will be ok??

Please respond if anybody knows about it.

Regards,
Mani