Actress Keira Knightley is auctioning the much-hyped green dress she wore in Oscar-nominated movie ATONEMENT to raise funds for a children's charity. The gown the 22-year-old's character wears in the romance's pivotal library sex scene is up for sale on the Clothes Off Our Back Foundation website. The non-profit organisation hopes to raise charity cash from the auction. Proceeds will go to Variety - The Children's Charity Of Southern California. Bidding, which currently stands at $3,000 (GBP1,500), will end on 1 March (08).