  The inverse amplitude method is used to unitarize the two loop $\pi\pi$
scattering amplitudes of SU(2) Chiral Perturbation Theory in the $I=0,J=0$,
$I=1,J=1$ and $I=2,J=0$ channels. An error analysis in terms of the low energy
one-loop parameters $\bar l_{1,2,3,4,}$ and existing experimental data is
undertaken. A comparison to standard resonance saturation values for the two
loop coefficients $\bar b_{1,2,3,4,5,6} $ is also carried out. Crossing
violations are quantified and the convergence of the expansion is discussed.
