Fans of Harry Potter are being offered the chance to win a walk-on part in the teenage wizard's next film.
Half-Blood Prince is Rowling's penultimate book in the series
The winner of a competition run by MSN will appear in forthcoming blockbuster Harry Potter And The Half-Blood Prince, which is due for release next year.
Questions about JK Rowling's best- selling book will be posted on the MSN website every week until 20 December.
MSN's Mike Lok said: "We're so excited about being able to offer this amazing prize to one Harry Potter fan."
"Needless to say, we expect this to be a highly contested competition," he added.
The contest is open to the site's UK users.
Harry Potter And The Half-Blood Prince is the sixth instalment in Rowling's hugely popular series.
Daniel Radcliffe will star once again as the schoolboy wizard, alongside Emma Watson and Rupert Grint, who play Hermione and Ron.
The film is due for release in November 2008.