The inspirational story of Welles Crowther, whose decision, determination and sacrifice in the terror of 9/11 have inspired millions, and whose short life offers a lasting lesson on character, calling, and courage--in how we live, and in the legacy we choose to leave behind   When Welles Crowther was a young boy in Nyack, NY, his father gave him a red handkerchief to keep in his back pocket, in case he ever needed it. He kept it with him on the way to church that day and nearly every day after. It was a fixture as he grew up, tucked in jeans or wrapped around his head as he played lacrosse for Boston College. The bandanna was a signature, long before it became a symbol.   Welles was like a lot of us, if just a bit better - an honors student, but not the valedictorian; a Division I athlete, but not a star; kindhearted but not saintly. He wanted the stuff of a good life and was willing to work for it. Fresh from college, he came to New York City for a job on Wall Street. His office was on the 104th floor of the World Trade Center.