subroutine adjnull( adj, add, x, nx,  y, ny )
integer ix, iy,     adj, add,    nx,     ny
real  			      x( nx), y( ny )
if( add == 0 )
	if( adj == 0 )
		do iy= 1, ny 
			y(iy) = 0.
	else
		do ix= 1, nx 
			x(ix) = 0. 
return; end