In this paper we consider two two-level atoms interacting with a two-mode lossy cavity. The effects of losses such as spontaneouse emissions of two-level atoms, photon absorption and scattering by the cavity mirrors are considered. Dynamical evolution of the quantum system is expressed by a master equation for density operator. We relate the probability to measure a photon in the considered two field modes with the photodetection probability theory as given by  the quantum trajectory and so we can see clearly the shape of the two modes of the extracted cavity field.