S. GREGORY JOY is a partner in the Washington, D.C. and the Atlanta offices of Smith, Currie & Hancock LLP.   Gregg has divided his practice between public and private contracting, having handled hundreds of construction, commercial and government contracts cases since 1984.Gregg has represented clients pursuing and defending against claims in federal and state courts, boards of contract appeals, administrative proceedings, arbitrations and mediations throughout the United States, placing an emphasis on trying to resolve claims to try to minimize risks and costs.   He has also helped contractors to obtain or maintain federal, state and local contracts through bid protests and SBA size protests and has successfully defended contractors whose accepted bids for contracts have been challenged.