Alex wrote letters to Barbara and other collectors of paintings by the artist Charisse, stating: 'I wish to sell my Charisse painting, entitled 'Dancer', and I would like it to go to someone like you, who will really appreciate it. I may be prepared to sell it to you for 75,000. Barbara immediately faxed a response, stating that she 'accepted Alex's offer'. Alex immediately sent a fax back stating that, "I am prepared to sell the painting to you, Barbara but, on second thoughts, for 80,000, and that price is open until 5.30pm on Wednesday: On the following Monday morning, Alex sold the Charisse painting to David, for 85,000. On Monday afternoon, Barbara saw in an internet chat room for art collectors that David had bought a Charisse painting. It did not identify the painting as 'Dancer'. On Tuesday morning, Barbara posted a correctly stamped and addressed letter, stating that she 'accepted Alex's offer' to sell her "his Charisse painting for 80,000 '. The letter arrived on Thursday morning. Advise Barbara as to her contractual position