integer
     $      id_tuple,                            ! ntuple ID number
     $      ltuple,                              ! length of ntuple
     $      current_run                          ! current run number

       parameter(
     $      id_tuple = 1,
     $        ltuple = 10)

       character*8
     $      tags_tuple(ltuple)                   ! ntuple varable names
       real
     $      tuple(ltuple)                        ! storage for ntuple entries
       
       data tags_tuple 
     $      /'run', 'amp', 'endx', 'lay', 'sec', 
     $       'nm',  'am',  'a2m',  'tm',  'tam'/

      integer
     $     mamp,                ! maximum number of amplitude bins
     $     mlay,                ! maximum number of layers
     $     msec,                ! maximum number of sectors
     $     mlen                 ! total dimension

      parameter(
     $     mamp = 20,           ! maximum number of amplitude bins
     $     mlay = 19,           ! maximum number of layers
     $     msec = 24,           ! maximum number of sectors
     $	   mlen = 2*mamp*mlay*msec) ! total dimension

      real
     $      nm(mamp,2,mlay,msec), ! number of entries
     $      am(mamp,2,mlay,msec), ! average amplitude
     $      tm(mamp,2,mlay,msec), ! average time
     $     a2m(mamp,2,mlay,msec), ! average amplitude**2
     $     tam(mamp,2,mlay,msec)  ! average amplitude*time

	common /user_twalk/
     $     tuple, 
     $     current_run,
     $     nm, am, tm, a2m, tam