  We present a dual two dimensional model for the Quantum Hall Fluid depending
on two parameters and show that this model has topologically non-trivial vacua
which are infrared stable fixed points of the Renormalization Group. The model
has a discrete (modular) symmetry which reproduces the fenomenological law of
corresponding states and allows for an unified description of the critical
points corresponding to Hall plateaus in terms of a 2 dimensional Conformal
Field Theory.
