law: Copyright Act, 1957 
  19. Mode of assignment – 
  [(Note: S.19 renumbered as sub-section (1)
  
  thereof by Act 23 of 1983, S.9 (w.e.f. 9-8-1984) (1)] No assignment of the
  
  copyright in any work shall be valid unless it is in writing signed by the
  
  assignor or his duly authorized agent.
  (2) [(Note: Subs. by Act 38 of 1994, S.8
  
  (w.e.f. a date to be notified) The assignment of copyright in nay work
  
  shall identify such work, and shall specify the rights assigned and the
  
  duration and territorial extent of such assignment.
  (3) The assignment of copyright in any work
  
  shall also specify the amount of royalty payable, if any, to the author or his
  
  legal heirs during the currency of the assignment and the assignment shall be
  
  subject to revision, extension or termination on terms mutually agreed upon by
  
  the parties.
  (4) Where the assignee does not exercise the
  
  rights assigned to him under any of the other sub sections of this section
  
  within a period of one year from the date of assignment, the assignment in
  
  respect of such rights shall be deemed to have lapsed after the expiry of the
  
  said period unless otherwise specified in the assignment.
  (5) If the period of assignment is not stated,
  
  it shall be deemed to be five years from the date of assignment.
  (6) If the territorial extent of assignment of
  
  the rights is not specified, it shall be presumed to extend within India.
  (7) Nothing in sub section (2) or sub section
  
  (3) or sub section (4) or sub section (5) or sub section (6) shall be
  
  applicable to assignments made before the coming into force of the Copyright
  
  (Amendment) Act, 1994.]