Author JK Rowling

British Author JK Rowling has revealed plans to write another 'Harry Potter' book.The seventh novel - 'The Deathly Hollows', due out in the summer - will bring the young wizard's adventures to an end, but Rowling has said she might write an eighth for charity.The 41-year-old writer wrote on her website: "I might do an eighth book for charity - a kind of encyclopedia of the world, so that I could use all the extra material that's not in the books."The book would allow fans a further insight into the world of Harry Potter and his friends, including details that were not included in the best-selling novels. Rowling has already penned two Harry Potter reference books - 'Quidditch Through The Ages' and 'Fantastic Beasts And Where To Find Them'.The books raised more than $30 million for British charity Comic Relief.The magical tales of Harry and his Hogwarts pals have made Rowling one of the highest earning writers ever, and one of the richest women in the world with an estimated fortune of 1 Billion according to Forbes magazine's annual rich list. As well as Comic Relief, the children's author supports numerous charities including medical charity Médecins Sans Frontières.