  We review two approaches to studying pseudoscalar meson-meson scattering
amplitudes to beyond 1 GeV using non-linear and linear chiral Lagrangians.
These approaches use two different unitarisation techniques - a generalised
Breit Wigner prescription and K-matrix unitarization respectively. We also
report some preliminary findings on K-matrix unitarisation of the I=J=0
pion-pion scattering amplitude in the non-linear chiral Lagrangian approach and
make some remarks about the light scalar mesons.
