Stocks showed modest gains in early-afternoon action Wednesday, erasing losses after upbeat comments from Washington about avoiding the fiscal cliff. The Dow Jones industrial average rose 0.5%, while the S&P 500 added 0.3%. The Nasdaq tacked on 0.2%, after being down nearly 1.1%. Volume was tracking up slightly from Tuesday's levels on both main exchanges. House Speaker John Boehner said he was optimistic that Washington could make a deal to avoid