real function pg_filt(xdummy)

         implicit none
         include 'ghib$data:cwn.inc'
         include 'c$inc:pivalu.inc'
         integer xdummy
         integer i,j,k
         integer nphotight,phoindex(10)
         real coriso

         pg_filt = 0.0
         nphotight = 0
         do i = 1,10
         phoindex(i) = 0
         enddo

         do i = 1,npho
           if (pchi(i).lt.20.0) then
           if (petc(i).gt.25.0) then
           if (abs(pcesz(i)).gt.14.0.and.abs(pcesz(i)).lt.217.0) then
           if (abs(pcesx(i)).lt.21.0) then
           if (pcesflg(i)) then
           if (pn3d(i).le.1.and.abs(ppt(i)).lt.1.0) then
           if (phadem(i).lt.(0.055+0.00045*pe(i))) then
           coriso = pco4(i)-pvcor(i)-plcor(i)*petc(i)
           if ((petc(i).ge.55.0.and.
     &          coriso.lt.2.0.and.btest(trigbits,17))
     &        .or.(petc(i).lt.55.0.and.
     &             pboxiso(i).lt.4.0.and.coriso.lt.2.0.and.
     &             btest(trigbits,15))) then
           if (psumpt4(i).lt.5.00) then
             nphotight = nphotight + 1
             phoindex(nphotight) = i
           endif
           endif
           endif
           endif
           endif
           endif
           endif
           endif
           endif
         enddo

C        final event cuts
         if (brcode.eq.15.or.brcode.eq.31) then
         if (vclassev.ge.12) then
         if (etout.eq.0.0) then
         if (nphotight.gt.0) then
         if (abs(pzv(phoindex(1))).le.60.0) then
           pg_filt = 1.0
         endif
         endif
         endif
         endif
         endif


         return
         end