c
      subroutine DiagSU(npts,P,ze,Zk,Wm,Wmst,Wm0,Wm0st
     &                 ,Mbare,f0,Uborn,zUborn,Urop,zUrop,Vsuper)

c     DiagSU calc the potential contributed by s and u channel diagrams
c**********************************************************************

      implicit none
c     LOCAL variables
      integer nch, npts1, cl
c     SHARED variables
      integer Nifty, npts, isXbon
      double precision P(64), Wm(64), Wmst(64), Uborn(64), Urop(64)
      double precision Cplv, Cplct, Cplcs, f0, Mbare(3), mpion, Mass
      double complex ze, Zk(2), zUborn(2), zUrop(2)
      double complex Wm0(2), Wm0st(2), Vsuper(128,128,6)

      common /control/ Nifty(15)
      common /couple/ Cplv(3,3),Cplct(2,2,2),Cplcs(2,2,2)
      common /mass/ mpion, Mass(2)

c***********************************************************************
c
      nch = Nifty(2)
      npts1 = npts + 1

c Func(Vsuper) is only initialized to zero once in VBag. Therefore
c everytime the PotFcn is called, Vsuper is updated (added on).
c
      if (Nifty(10) .ge. 1) then
c 	s-channel diagram contributes to P11(N), P33(Delta) waves only
c       P11(N):
        if ((Nifty(4).ne.4) .or. (Nifty(6).eq.3)) then
	  isXbon = 0
      	  cl = 3
          call PotFcn(isXbon, cl, npts, ze, P, Zk, Wm, Wmst, 
     &  Wm0, Wm0st, Mbare, f0, Uborn, zUborn, Urop,zUrop,Vsuper)
        endif
c
c       P33(Delta):
        if ((Nifty(4).ne.4) .or. (Nifty(6).eq.6)) then
	  isXbon = 0
	  cl = 6
          call PotFcn(isXbon, cl, npts, ze, P, Zk, Wm, Wmst, 
     &  Wm0, Wm0st, Mbare, f0, Uborn, zUborn, Urop,zUrop,Vsuper)
        endif
      endif

      if (Nifty(10) .ge. 2) then
c       u-channel diagram contributes to all 4 p waves, isXbon = 1
c       P11, cl = 3
        if ((Nifty(4).ne.4) .or. (Nifty(6).eq.3)) then
          call PotFcn(1, 3, npts, ze, P, Zk, Wm, Wmst, Wm0, Wm0st,
     &    Mbare, f0, Uborn, zUborn, Urop, zUrop, Vsuper)
        endif

c       P31, cl = 4
        if ((Nifty(4).ne.4) .or. (Nifty(6).eq.4)) then
          call PotFcn(1, 4, npts, ze, P, Zk, Wm, Wmst, Wm0, Wm0st,
     &    Mbare, f0, Uborn, zUborn, Urop, zUrop, Vsuper)
        endif

c       P13, cl = 5
        if ((Nifty(4).ne.4) .or. (Nifty(6).eq.5)) then
          call PotFcn(1, 5, npts, ze, P, Zk, Wm, Wmst, Wm0, Wm0st,
     &    Mbare, f0, Uborn, zUborn, Urop, zUrop, Vsuper)
        endif

c       P33, cl = 6
        if ((Nifty(4).ne.4) .or. (Nifty(6).eq.6)) then
          call PotFcn(1, 6, npts, ze, P, Zk, Wm, Wmst, Wm0, Wm0st,
     &    Mbare, f0, Uborn, zUborn, Urop, zUrop, Vsuper)
        endif
      endif
      return
      end