A federal judge in Boston yesterday rejected a lawsuit filed by six members of Congress that aimed to prevent the Bush administration from attacking without a declaration of war from Congress. Meanwhile, in Washington, peace activists are taking a different approach to stopping the war by organizing a virtual march on Washington tomorrow. The web-based group MoveOn.org is asking supporters to log on to its website, MoveOn.org, to be assigned a time to call their representative in order to flood the congressional switchboard with antiwar voices. In antiwar protests in Britain, Greenpeace activists shut down over 100 Esso stations and the British headquarters of Exxon.