I live in Georgia, I have a condo is under water, if I walk away, will the lender take the condo, sell it and still after me for the diffrence I own?

If you stop making the mortgage payment, the lender can foreclose.  Mortgage companies tend to be taking longer to foreclose on condos than single family homes.  After the foreclosure, the mortgage that foreclosed (usually the first mortgage) has to file a Confirmation of the foreclosure to collect on any deficiency.  If you have any other liens on the property, they do not have to file a Confirmation to collect.  Many people are better off surrendering their house in a Chapter 7 bankruptcy.