U.S. stock indexes opened with tentative gains Monday with the Dow Jones industrial average flat on the first trading day of the second quarter., After a gain of 8.14 percent in the first quarter, the DJIA added 1.21 points to 13,213.25, a gain of 0.01 percent. The Nasdaq composite index added 8.25 points, to 3,099.82, up 0.27 percent. The Standard and Poor\'s 500 index picked up 3.49 points to 1,411.96, a 0.25 percent gain. The 10-year treasury note was yielding 2.187 percent as prices rose 7/32. The euro was 1.3297 from Friday\'s $1.3343. Against the yen, the dollar was 82.27 from Friday\'s 82.82. In Tokyo, the Nikkei 225 index gained 0.26 percent, 26.31 points, to 10,109.87.