REAL FUNCTION coin_hbook()
      IMPLICIT NONE
      INCLUDE ?

      LOGICAL FIRST
      DATA FIRST /.TRUE./
      SAVE FIRST
      real haero_tot
      real wlocut,whicut,q2min,thetacm,csum
      logical good_electron,good_pion
      logical good_pion1
      logical coint_e_pi,coint_e_pi_delta
      logical mmcut_relax,good_ran
c

      IF(FIRST) THEN
         FIRST=.FALSE.
         PRINT *,  'BOOKING HISTOS...'
         CALL HBOOK1(3,'scal E1 track t=scleantrack',
     ^100,0.0,1.5,0)
         CALL HBOOK1(4,'scal Etot track t=scleantrack',
     ^100,0.0,2.0,0)
         CALL HBOOK1(5,'scer npe t=scleantrack',100,0.,15.,0)  
         CALL HBOOK1(6,'sbeta t=scleantrack',100,0.5,1.2,0)
         CALL HBOOK2(7,'scal x vs Etot t=scleantrack',
     ^100,0.0,2.0,100,-60.0,60.0,0)        
         CALL HBOOK2(8,'scal y vs Etot t=scleantrack',
     ^100,0.0,2.0,100,-30.0,30.0,0)        



         CALL HBOOK1(13,'hbeta t=hclean',100,-1.,1.5,0)
         CALL HBOOK1(14,'HMS s1xdedx t=hclean',100,0.0,800.,0)
         CALL HBOOK1(15,'HMS TOFmass2 t=hclean',100,-1.,4.0,0)

         CALL HBOOK1(22,'haero-pos-npe-sum t=hclean',100,0.0,40.,0)
         CALL HBOOK1(23,'haero-neg-npe-sum t=hclean',100,0.0,40.,0)
         CALL HBOOK1(25,'haero-tot-npe-sum t=hclean',100,0.0,40.,0)

         CALL HBOOK1(32,'hcer adc bottom t=hcelan',100,0.0,400.,0)
         CALL HBOOK1(33,'hcer adc top t=hclean',100,0.0,400.,0)
         CALL HBOOK1(34,'hcer npe sum t=hclean',100,0.0,40.,0)
         CALL HBOOK2(35,'xcer vs hcer_npe t=hclean',100,0.0,20.,
     ^100,-70.,70.,0)

        
         CALL HBOOK2(50,'HMS beta vs Cointime t=e pi',100,-10.,
     ^10.,100,0.8,1.2,0)
         CALL HBOOK2(51,'SOS beta vs Cointime t=e pi',100,-10.,
     ^10.,100,0.8,1.2,0)
         CALL HBOOK1(53,'SOS-HMS path corr(ns) t=e pi',100,-2.0,2.0,0)
         CALL HBOOK2(54,'HMS ztgt vs SOS ztgt t=e pi',100,-8.,8.
     ^,100,-8.,8.0,0)
       
       CALL HBOOK1(62,'Mm(pi prod) t=coint e pi delta',100,0.0,1.5,0)
       CALL HBOOK1(63,'Em t=coint e pi delta',100,-0.4,2.4,0)
       CALL HBOOK1(64,'Eexc t=coint e pi delta',100,-0.3,0.3,0)

         CALL HBOOK1(65,'Q2 t=mmcut relax',100,1.0,4.,0)
         CALL HBOOK1(66,'W t=mmcut relax',100,1.5,3.,0)
         CALL HBOOK2(67,'W vs Q2 t=mmcut relax',100,1.4,
     ^3.5,100,1.9,2.6,0)
         CALL HBOOK2(68,'-t vs phipi t-mmcut relax',100,
     ^-0.5,0.5,100,-0.5,0.5,0)
          

        CALL HBOOK1(101,'t, t=mmcut relax',100,0,0.8,0)
        CALL HBOOK1(102,'phipi, t=mmcut relax',100,0.,6.28,0) 

         CALL HBOOK1(2001,'hsdelta t=hclean',100,-20.0,20.0,0)
         CALL HBOOK1(2002,'ssdelta,t=sclean',100,-20.0,20.0,0)

         CALL HBOOK1(3000,'Cointime t=e pi',100,-10.,10.,0)
        ENDIF
  
       haero_tot=haero_po+haero_ne
  
         good_electron = .false.
         if(scer_npe.gt.1.0.and.ssshtrk.gt.0.7)
     ^good_electron = .true.
         good_pion1 = .false.
         if(hcer_npe.lt.0.2.and.haero_tot.gt.4.)
     ^good_pion1 = .true.
         good_pion = .false.
         if(good_pion1.and.hsmass2.lt.1.0) good_pion= .true.
 
         coint_e_pi = .false.
      if(abs(cointime).lt.3.5.and.good_pion.and.good_electron)
     ^coint_e_pi=.true.

        coint_e_pi_delta = .false.
      if(coint_e_pi.and.abs(hsdelta).lt.8.5.and.abs(ssdelta).lt.15.)          
     ^coint_e_pi_delta= .true.  
          mmcut_relax = .false.
      if(coint_e_pi_delta.and.abs(missmass-0.939).lt.0.05)
     ^mmcut_relax=.true.    

      good_ran=.false.
      if(good_pion.and.good_electron.and.abs(hsdelta).lt.8.5.and.
     ^abs(ssdelta).lt.15.0.and.abs(missmass-0.939).lt.0.05) then

         good_ran=.true.
      endif
      

      CALL HFILL(3,ssprtrk,0.,1.)
      CALL HFILL(4,ssshtrk,0.,1.)
      CALL HFILL(5,scer_npe,0.,1.)
      CALL HFILL(6,ssbeta,0.,1.)
      CALL HFILL(7,ssshtrk,scal_x,1.0)
      CALL HFILL(8,ssshtrk,scal_y,1.0)

      CALL HFILL(13,hsbeta,0.,1.)
      CALL HFILL(14,hsdedx1,0.,1.)
      CALL HFILL(15,hsmass2,0.,1.)
    
      CALL HFILL(22,haero_po,0.,1.)
      CALL HFILL(23,haero_ne,0.,1.)
      CALL HFILL(25,haero_tot,0.,1.)

      CALL HFILL(32,hceradc1,0.,1.)
      CALL HFILL(33,hceradc2,0.,1.)
      CALL HFILL(34,hcer_npe,0.,1.)
      CALL HFILL(35,hcer_npe,hcersx,1.)
     
      CALL HFILL(2001,hsdelta,0.,1.)
      CALL HFILL(2002,ssdelta,0.,1.)
    
      if(good_pion.and.good_electron)then
      CALL HFILL(50, cointime,hsbeta,1.)
      CALL HFILL(51, cointime,ssbeta,1.)
      CALL HFILL(53, coinpath,0.,1.)
      CALL HFILL(54,sszbeam,hszbeam,1.)
      endif     

      if(coint_e_pi_delta)then
      CALL HFILL(62, missmass,0.,1.)
      CALL HFILL(63, Em,0.,1.)
      CALL HFILL(64, Eexc,0.,1.)

      endif
      
      if(good_ran) then
         CALL HFILL(3000,cointime,0.,1.)
      endif
      if(mmcut_relax)then
      CALL HFILL(65, Q2,0.,1.)
      CALL HFILL(66, W,0.,1.)
      CALL HFILL(67, Q2,W,1.)
      CALL HFILL(68,ctphix,ctphiy,1.)
      CALL HFILL(101,t,0.,1.)
c      print*, 'phi_pq=',phi_pq 
      CALL HFILL(102,phi_pq,0.,1.)

      endif

      coin_hbook = 1.
      return
      end