Visitor visa extsn for in-laws and the same time visa interview for parents

[GeethGubi]

My in-laws have come to US in visitor visa in Apr 09 and staying here. Their I-94 is expiring in 4rth Oct 09. As we have some places (west coast) yet to see, I would like to extend their visa. At the same time, I want to bring my parents. Its been long time since I have seen them so I want to keep them here for sometime. My in-laws are planning to leave in Nov and my parents are coming here in Dec. So the question is

1. This being the case, shall I send my parents for the visa interview their in India when my in-laws are here waiting for their extension?
2. Will it be a problem for any case (visa interview or visa extn appln) when I file the visa extension simultaneous to the Visa interview booking for my parents there in India?

[immihelp]

1. It does not matter.
2. No, as long as you have money to support all of them.