Section 2(a) of the Indian contract Act states that when one person signifies to another his willingness to do or to abstain from doing anything, with a view to obtaining the assent of that other to such act or abstinence, he is said to make a proposal. In the given case, X made a statement in an uninhabited hall regarding selling his mobile phone for Rs.1000 and it was not made or addressed to anyone. So, this does not amount to a valid proposal.