  In this paper we first prove a Clark--Ocone formula for any bounded
measurable functional on Poisson space. Then using this formula, under some
conditions on the intensity measure of Poisson random measure, we prove a
variational representation formula for the Laplace transform of bounded Poisson
functionals, which has been conjectured by Dupuis and Ellis [A Weak Convergence
Approach to the Theory of Large Deviations (1997) Wiley], p. 122.
