Before dealing further having regard to the Section 4 of the TP Act, which stipulates that the provisions of the TP Act relating to contract shall be taken as part of the Indian Contract Act, 1872, a reference need to be made to relevant provisions of the Contract Act. The Indian Contract Act is not a complete code dealing with law of contracts. Whenever the provisions of the Contract Act do not apply the principles of English Law in turn would apply. (See Bhavandas v Girdharlal & Co. ,[29] and Superintendence Co of India v Krishna Murga i[30] ) . Be that as it is, sale of immovable property being contract, it is necessary to recapitulate the basic principles of contract. An agreement enforceable by law is a contract and agreement not enforceable by law is void, though an agreement enforceable at the option of one or more parties thereto becomes voidable. All agreements become contracts when there is a valid proposal and reciprocal acceptance of the proposal agreeing with the conditions subject to which one party makes the proposal and the other party accepts such proposal. A person who is of sound mind and who is not disqualified by any law is alone competent to contract. Sections 13, 14, 15, 16, 17, 18 and 19 of Contract Act define and explain the terms often used in the law of contract, namely, “consent”, “free consent”, “coercion”, “undue influence, “fraud” and “misrepresentation” respectively. Sections 20, 24 to 30 describe the agreements/contracts, which are void. These are: (a) where both parties to an agreement are under a mistake as to the matter of fact essential to the agreement; (b) if the consideration and object of a contract is unlawfu l[31] ; (c) an agreement without consideration is void subject to certain exceptions contained in Section 25; (d) agreement in restraint of marriage of a person other than a minor; (e) an agreement restraining the other from exercising a lawful profession, trade or business; (f) an