  We present a method to solve the Helmholtz equation for a non-homogeneous
membrane with Dirichlet boundary conditions at the border of arbitrary
two-dimensional domains. The method uses a collocation approach based on a set
of localized functions, called "little sinc functions", which are used to
discretize two-dimensional regions. We have performed extensive numerical tests
and we have compared the results obtained with the present method with the ones
available from the literature. Our results show that the present method is very
accurate and that its implementation for general problems is straightforward.
