A NEW cassette tape, called Coping with Pain, has been made for for Britain's 8 million arthritis sufferers. The tape was produced by Magnus Magnusson, host of Mastermind, and the Falklands veteran Simon Weston, and was developed at the pain relief clinic at Walton Hospital, Liverpool. It includes relaxation techniques and exercises to stimulate the body's natural painkillers. Cost is pounds 6.75, including postage, from Pain Tape, PO Box 1, Wirral L47 7DD.