law: Hindu Marriage Act, 1955
  25.Permanent alimony and maintenance.-
  (1) Any court exercising jurisdiction under this Act may, at the
  
  time of passing any decree or at any time subsequent thereto, on application
  
  made to it for the purpose by either the wife or the husband, as the case may
  
  be, order that the respondent shall, while the applicant remains unmarried, pay
  
  to the applicant for her or his maintenance and support such gross sum or such
  
  monthly or periodical sum for a term not exceeding the life of the applicant
  
  as, having regard to the respondent's own income and other property, if any,
  
  the income and other property of the applicant and the conduct of the parties,
  
  it may seem to the court to be just, and any such payment may be secured, if
  
  necessary, by a charge on the immovable property of the respondent.
  (2) If the court is satisfied that there is a change in the
  
  circumstances of either party at any time after it has made an order under
  
  sub-section (1), it may, at the instance of either party, vary, modify or
  
  rescind any such order in such manner as the court may deem just.
  (3) If the court is satisfied that the party in whose favor an
  
  order has been made under this section has remarried or, if such party is the
  
  wife, that she has not remained chaste, or, if such party is the husband, that
  
  he has had sexual intercourse with any woman outside wedlock, it shall rescind
  
  the order.