Where formula_38 is the order parameter at the border between (2) and (l), formula_39 the so-called extrapolation length and formula_40 a constant that enters the model and has to be determined using experiment and other models. Hence one can see that the order parameter in the liquid film can undergo a continuous phase transition for large enough extrapolation length. A further result is that formula_41 what corresponds to the result of the thermodynamical model in the case of short range interactions.