Harry Potter author JK Rowling said Thursday she would love to become invisible.

"I would love the power of invisibility. It is a little bit sad but I would sneak off to a cafe and write all day", she said, appearing live at London's Royal Albert Hall.

Rowling was interviewed by British comedian Stephen Fry who then introduced questions from children around the world, some sent by e-mail and others filmed.

Rowling provoked the astonishment of all 4,000 children in the audience by saying that the world's most famous boy wizard may not survive until adulthood.

When asked by a boy from Sydney if there would be any books about Harry as an adult, she said "You have to wait and see if he survives to be a grown-up. I don't want to give anything away at the moment."

Last Saturday the fifth Harry Potter book "Harry Potter and the Order of the Phoenix" went on sale in the UK, US, Canada, Australia and in English in many other countries around the world.

One hundred copies of the new Harry Potter book were available in Bulgaria during its world premiere. The official launching of the Bulgarian translation of the book has been scheduled for December 13.