cross product

Given a cartesian equation of a plane M and a vector equation of a line l . I am asked to find the cartesian equation of another plane N , given a point on this plane. We are told also that plane N is parallel to line l and perpendicular to plane M. My question is what will be the order to find the cross product of the direction vector of l with the normal vector to plane M. l cross M or M cross l ? Thanks in advance!!