May authorises Jack, her agent, to sell May's antique diamond ring for not less than 3,000 and to purchase twenty plasma screens for May's business for up to 6,000. Jack buys the ring himself for 3,000 using a nominee and then sells it on to a dealer for 4,000. Jack keeps the 1,000 he has made. Jack, who is well known at Dixons plc as an agent for May, contracts to buy ten plasma screens from them for 7,500.

Give detailed advise to May whether she can sue Jack or not on the light of Jack's behaviour, and conducts.