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