A numerical method is presented for modeling the photodissociation of nitric oxide in the mesosphere and the relevant part of the stratosphere. By using the following simple formula JNO=J∞exp {-(1.0+0.125-0.175)10-8 [F∞zn(O2)d1>0.38} it is possible to obtain sufficiently realistic photodissociation rates which are in reasonable agreement with detailed calculations. In the stratosphere, the effects of ozone absorption and of molecular nitrogen de-excitation must be introduced.