Several All-Americans were decided today as action continued in the Asics Junior National Championships at the FargoDome in Fargo, N.D.     In the 98-pound pool, Matt Gardner of Oregon, Sandeep Kumar of New York, Shane Walton of Minnesota, Cash Coolidge of Nebraska and Luke Seger of Indiana all advanced to Tuesday's medal round. Seger guaranteed at least a silver medal for himself by advancing to the finals.    Three wrestlers also advanced to the medal round of the 165-pound bracket, guaranteeing them All-American status. Paul Bergman of Ohio and A.J. Morgan of Wisconsin will meet to battle for seventh place, while Mashall Marquardt of Iowa will wrestle in the fifth-place final.     In other action, the defending national champions at the Junior Greco-Roman level continued dominating their field.    Defending champion Harry Lester swept through the 132-pound weight class, winning all five of his matches, four of them by technical fall.     Cam Jones of Utah is giving Lester a run for his money in the 132-pound weight class, though, also winning all five of his matches. He won three by technical fall and two with pins.    Retuning champion Matt Nagel has still yet to allow a point in his impressive run through the 154-pound field. He won three matches by technical fall and two by pin to improve his record to 8-0 during the tournament.     Junior action resumes Tuesday at 9 a.m. central daylight time with the final round of preliminary action. The medal rounds begin at 4 p.m. with the finals scheduled for 6:15 p.m.     Live action updates of the finals will be available on the TheMat.com.