  We study a simple higher-dimensional toy model of electroweak symmetry
breaking, in particular a pure gauge 5D theory on flat background with one
extra finite space dimension. The principle of least action and the requirement
of gauge independence of scattering amplitudes are used to determine the
possible choices of boundary conditions. We demonstrate that for any of these
choices the scattering amplitudes of vector bosons do not exhibit power-like
growth in the high energy limit. Our analysis is an extension and
generalization of the results obtained previously by other authors.
