I live in new jersey and just filed chapter 7. can I keep my home?

what is the homestead exemption law in new jersey. and does it allow you to keep your home and do a loian modification if your in a chapter 7.
my home is underwater I owe 400000 and it is worth 250000.

From the link at the bottom:

"Residents of New Jersey can choose between New Jersey state law exemptions and federal law exemptions. Since New Jersey does not recognize a homestead exemption, New Jersey debtors can select the federal bankruptcy homestead exemption providing for up to $20,200 for the debtor's principal residence. When calculating your equity you should use a value that is based upon a fair market valuation. Once you determine this value, subtract the amount owed plus selling and transfer costs from the value to calculate the equity."

http://www.njlawconnect.com/newjerseybankruptcy.chapter7.faq.htm#12