We write the bills that become laws

Executive Branch agencies issue regulations with the full force of law, but these are only under the authority of laws enacted by Congress. The President may veto bills Congress passes, but Congress may also override a veto by a two-thirds vote in both the Senate and the House of Representatives. So therefor they made the bills that became laws. 

A legislative proposal that if passed by both house and senate then approved by the president becomes a law. hope that helps