Section 402. Pleadings

There shall be a petition, which shall comply with
  the requirements for a complaint in an action, and an answer where there
  is  an  adverse  party.  There  shall  be  a  reply  to  a  counterclaim
  denominated as such and there may be a reply to new matter in the answer
  in any case. The court may permit such other pleadings as are authorized
  in  an  action  upon  such  terms  as  it may specify. Where there is no
  adverse  party  the  petition  shall  state  the  result  of  any  prior
  application  for similar relief and shall specify the new facts, if any,
  that were not previously shown.