To constitute an offer, the offeror must intend to create a legal obligation, or he must appear to intend to create a legal obliga­tion.  This intent can be shown by conduct.  For example, when one party signs a written contract and sends it to the other party, this action is obviously an offer to enter into a contract on the terms of the writing.  Again, the offeror must intend to create a legal obligation.  No contract comes into being when an offer is made jokingly, or under any other circumstances that would cause a reasonable person to believe there was no intent to enter into a binding agreement.