The Christmas and New Year edition of the Radio Times, on sale this week, is the festive double issue, priced £1.55. Sales of around three million copies are expected in the biggest revenue-earning event in the magazine market. Harry Potter has cast his spell because, for the first time in the publication's history, the Christmas cover is devoted to a single radio programme. It is the first adventure of J K Rowling's blockbuster character and will be read by actor Stephen Fry, unabridged and uninterrupted, in an eight and a half hour broadcast on Radio 4 on Boxing Day. Programmes run from December 23 to January 5. {{CTN }}