  In the framework of a QCD relativistic potential model we evaluate the form
factors describing the exclusive decays B => \pi l nu and B => K l+ l-. The
present calculation extends a previous analysis of B meson decays into light
vector mesons. We find results in agreement with the data, when available, and
with the theoretical constraints imposed by the Callan-Treiman relation and the
infinite heavy quark mass limit.
