Article 143 of the Civil Code is valid if a civil juristic act meets the following conditions: (1) The actor has corresponding capacity for civil conduct; (2) the meaning is true; (three) does not violate the mandatory provisions of laws and administrative regulations, and does not violate public order and good customs. Article 469 The parties may conclude a contract in writing, orally or in other forms. Written form refers to contracts, letters, telegrams, telexes, faxes and other forms that can tangibly express the contents contained. A data message that can tangibly express its content through electronic data interchange, e-mail, etc. , and can be retrieved at any time, are considered in writing.