SUBROUTINE KNINSW(IK, TRKW, VTRKW, IDTYP, LXYZ, LMFIX, CLASID)
 
C  >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
C   Inserts a particle in the KN list.
C
C  IK        Integer variable (read)
C            KN track number to store info.
C
C  TRKW      real array (read)
C            Parameters in W format (Px,Py,Pz,E,x,y,z)
C
C  VTRKW     real array (read)
C            Covariance matrix of TRKW (assumed to be 7x7)
C
C  IDTYP     Integer variable (read)
C            Particle type
C
C  LXYZ      Logical variable (read)
C            TRUE  ==> position info can be used in fit
C            FALSE ==> position info cannot be used in fit
C            Position info is always stored.
C
C  LMFIX     Logical variable (read)
C            TRUE  ==> mass is fixed (fixed during track updates)
C            FALSE ==> mass is floating
C
C  CLASID    Integer variable (read)
C            User defined ID number (stored in ICLSKN)
C  >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>