C a common block is used at particle ID.
        COMMON/PARTIDP/IDGDTOF,IDGDDEDX,IDGDCOM,TOFCHI(3),DEDXCHI(3),
     &   COMCHI(3),PROBILITY(3),XPIK,
     &   XXSP(3), XDEDXOFF(3),XDEDXSIG(3),
     &   YXSP(3), YDEDXOFF(3),YDEDXSIG(3)
C
        INTEGER IDGDTOF,IDGDDEDX,IDGDCOM
        REAL TOFCHI,DEDXCHI,COMCHI,PROBILITY,XPIK,
     &       XXSP, XDEDXOFF,XDEDXSIG,
     &       YXSP, YDEDXOFF,YDEDXSIG
C
C       idgdtof  , =1,good for tof information;otherwise =0
c       idgddedx , =1,good for dedx information;otherwise =0
c       idgdcom  , =0,none of two information is used.
c                , =1,one of two information is used.
c                , =2,two information is used.
c       tofchi   , tof chi squre of the particle.
c       dedxchi  , dedx chi squre of the particle.
c       comchi   , the sum of the two chis squre of the particle.
c       probility , the probility of the particle.
c       xpik     ; probk/(probpi+probk)
