Rules concerning child custody in Texas fall under chapters 152 and 153 of the family code. These laws state that the policy of the court is to ensure that a child has frequent contact with both parents. Exceptions are made when there is evidence that this contact would be harmful to the child. In addition, the law confirms that no custody or visitation decisions can be made contingent on a parent paying child support. Chapter 153 also states that sex of the parent and his/her married status will not be a given any weight in determining which parent should be granted child custody. Texas courts encourage parents to enter into a written agreement or "parenting plan" themselves rather than having a judge decide the details. The court must still approve this plan for it to become legally binding. In some cases, the parents may be asked to revise their plan if the court determines that the agreement is not in the best interests of the child. Mediation may be ordered if parents are unable to reach an agreement.