subroutine qqb_2jet_swap(pin,msq)
c--- this is just a wrapper routine to qqb_dirgam_g,
c--- that interchanges p3 and p4 before the call
      implicit none
      include 'constants.f'
      integer nu
      double precision pin(mxpart,4),msq(-nf:nf,-nf:nf),
     & pswap(mxpart,4)
     
      pswap(:,:)=pin(:,:)
      pswap(3,:)=pin(4,:)
      pswap(4,:)=pin(3,:)
      
      call qqb_2jet(pswap,msq)
      
      return
      end