function [y,ny] = delay(x,nx,n0)
N = length(nx);
if n0 >= 0
    ny = [ nx(1):nx(1)+N+n0-1 ];
elseif n0 < 0    
    ny = [ nx(1)+n0:nx(1)+N-1 ];
end;
M = length(ny);
y = zeros(size(ny));
if n0 > 0
    y(n0+1:M) = x;
else
    y(1:M+n0) = x;
end