Despite heavy competition from racism, sexism and homophobia, there may be no more widespread form of discrimination today than ageism. Ageism is, of course, the pernicious belief that older people are forgetful, infirm and fanatically devoted to watching reruns of "Matlock." Yet, this is patently untrue. I know for a fact that some older viewers prefer the Dick Van Dyke program, "Diagnosis: Murder."