Symbiotic stars and quasars exhibit prominent $H{alpha}$ emission lines often accompanied with broad wings. $H{alpha}$ emission nebulae in these objects are proposed to be optically thick to resonance scattering. The transfer of $H{alpha}$ line photons are further complicated by the existence of another scattering channel leading to re-emission of $Ly{eta}$. In this work are develop a Monte Carlo code to simulate the transfer of $H{alpha}$ line photons incorporating the scattering channel into $Ly{eta}$. We show various line profiles of $H{alpha}$ and $Ly{eta}$ emergent from our model nebulae. It is shown that temperature is a critical parameter which controls the ratio of emergent $Ly{eta}$ flux to that of $H{alpha}$.