visitor visa to my adopted parents

Hi,

My Husband would like to sponsor my adopted parents here to U.S for a six month stay.over the web sites i read that along with the persond passport details we need to submit the girls passport details.But I havew no legal document to prove that they are my parents.They are my uncle and aunt who brought me up.Their surname and my surname are different.
what do I do.

Please let me know soon.

luv

Venus Orchid

If you have no documents to prove that they are your parents, why no say that they are your aunt and uncle and sponser them visa which is way simple and straight forward.
You will get tourist visa for 10 years if you can prove that they have a job/property/kids there and ensure that they will surely to India after the trip.