U.S. markets are down at midday on Thursday after failing to keep their modest gains from earlier in the session on signs the conflict in Ukraine is escalating. Stocks were initially propped-up by this morning's weekly jobless claims report from the labor department which showed that fewer Americans filed for unemployment benefits. Investors will get fresh economic data at 3pm ET when figures on consumer credit are released. Google (GOOG) and Barnes & Noble (BKS) are joining forces to take on Amazon (AMZN). The two companies will offer same-day delivery of thousands of books. Shares of Barnes & Noble are up more than 2 percent. Keurig Green Mountain (GMCR) is just slightly higher after reporting its quarterly profit beat estimates. The k-cup maker also raised its full-year outlook. After today's close, CBS (CBS), NewsCorp (NWSA) and online game maker Zynga (ZNGA) are set to report quarterly results. TheStreet's Susannah Lee reports from New York.