subroutine zero(X)
#include "global_dims.inc"
      real X(ilow:ihigh,jlow:jhigh,klow:khigh)
c
#ifdef DEBUG_MODE_ON
      write(*,*) "DEBUG:  in zero.F::zero(X)"
#endif
c
      if ( .not. MHD_PE ) return
      do k=klow,khigh
         do j=jlow,jhigh
            do i=ilow,ihigh
               X(i,j,k) = 0.
            enddo
         enddo
       enddo
c
       return
       end