  We present a method for calculating the photoproduction of jets at HERA based
on Next to Leading Logarithm QCD calculations. It is implemented in a
Monte-Carlo generator which allows us to easily compute any infra-red safe
cross sections for 1 or 2 jet observables using various jet reconstruction
algorithms. We focus on the possibility of extracting the gluon contents of the
photon and of the proton from present and future H1 and ZEUS data.
