8.16.1 flag(n_ch,n_ph,low,high)

flag $<$ test1 $<$ BoaTest1.f90

! NAM: test1.flag  (sub)
! VER: 9.12.03 f.bertoldi initial
!      9.02.04 fb now flag outside range
! DES: only for testing and illustration
!      set flag for given channel if data <low or >high 
! INP: channel = channel number for which data to be flagged
!      low     = lower limit 
!      high    = upper limit
! OUT:
! HIS: FB040303  change to _p