error C2447: missing function header (old-style formal list?)

   An   open   curly   brace   ({)   was   found   at   global   scope   without   a   corresponding   function   header.  
   
  This   error   can   be   caused   by   using   the   old-style   C-language   formal   list.  
   
  Check   that   the   function   being   defined   has   an   appropriate   function   declaration.  
   
  The   following   is   an   example   of   this   error:  
   
  int   c;  
  {}