The agreement only has a signature and is valid as long as it meets the legal requirements for validity. According to the provisions of Article 143 of the Civil Code, civil legal acts are valid if they meet the following conditions: (1) The actor has the corresponding capacity for civil conduct; (2) The expression of intention is true (3) It does not violate laws and administrative regulations The mandatory provisions of laws and regulations do not violate public order and good customs. Article 153 stipulates that civil legal acts that violate the mandatory provisions of laws and administrative regulations are invalid. However, this mandatory provision does not invalidate the civil legal act. Civil legal actions that violate public order and good customs are invalid. Article 490 of the "People's Republic of China and Civil Code" If the parties conclude a contract in the form of a contract, the contract shall be established when both parties sign, seal or fingerprint. Before signing, sealing or fingerprinting, one party has performed its main obligations and the contract is established when the other party accepts it. Laws and administrative regulations stipulate or the parties agree that a contract should be concluded in written form. If the parties do not use written form but one party has performed its main obligations and the other party accepts it, the contract is established.