Television is undoubtedly a great invention , but one of the main criticisms of it is that people just aren't selective enough . Lesley , got a television . how do you pick out the sorts ofprogrammes you want to watch ?   I try and look at the programmes that are on to decide which particular ones interest me , rather than you turning it on a seven o'clock and you leaving it on until half-past eleven when the programmes finish .   Do you think of television though as a great time-waster ? 