1. Offer - the manifestation of a willingness to enter into a contract
which justifies the offeree in believing that his acceptance will
create a contract.
The person who made the offer is the offeror; the person who the
offer is made to is the offeree.
2. Acceptance - an offeree’s assent, either express or by
implication from conduct, to the terms of an offer in a manner
authorized or requested by the offeror.
3. Intention - the contracting parties intend to create legal relations.
4. Legal capacity – the person who make an agreement must have
the ability to do such things.
5. Lawful purpose – the objects of the agreement must not illegal,
impposible contrary to public order or morals.