Since it was a very cold winter and Mr Ellis urgently needed power to run the heater, on 27 October 2012 he went to Home Depot to buy a portable petrol generator. The store had only one portable generator left. That was an EG3600CX generator, and it had been used by the store as a demonstration model. Mr Ellis was interested in the EG3600CX generator and he asked the salesman: "Is that for sale?" The sales man responded that "No. It is for demonstration only, but I will check with my boss". After talking to his boss, the salesperson told Mr Ellis that "we can sell it to you for $4000. we can deliver it to your property and you can pay upon delivery". Mr Ellis told the saleperson that "can you keep it for me for two days? I need some more tiems to think about whether it is the right generator for my property". The saleperson agreed. When Mr Ellis left the store, another customer came and wated to buy the EX3600CX generator for $5000. Home Depot immediately sold the generator to that customer. On 29 October 2012, Mr Ellis called the salemand at Home Depot and told him that "I accept your offer . Please deliver the generator to my property at 65 James Street, Red Hill. I will pay $4000 upon delivery". After hearing that, the salesman told Mr Ellis that the generator was already sold. Mr Ellis was very unhappy. He insisted that the store must deliver the generator to him.

In this case, can you please discuss possible legal Issue?