NEW YORK -- J.K. Rowling says her efforts to halt a publisher's "Harry Potter" lexicon have been crushing her creativity.

Rowling says she has stopped work on a new novel. She says her federal court case has "decimated my creative work over the last month."

Rowling is suing RDR Books to stop publication of Steven Vander Ark's "Harry Potter Lexicon."

She told the court on today, "This book constitutes wholesale theft of 17 years of my hard work."

RDR's lawyer, Anthony Falzone, defends the lexicon as a reference guide. Falzone calls it a legal effort "to organize and discuss the complicated and very elaborate world of Harry Potter."

When Rowling's lawyer asked how she felt about Harry, she replied: "I really don't want to cry." But she looked like she was about to do just that.