  We report on our reexamination of the radiative corrections to $\pi_{l2}$ and
$K_{l2}$ decays. We perform a matching calculation, using a specific model with
vector meson dominance in the long distance part and the parton model in the
short distance part. By considering the dependence on the matching scale and on
the hadronic parameters, and by comparing with model independent estimates, we
scrutinize the model dependence of the results. For the pseudoscalar meson
decay constants, we extract the values $f_\pi = (92.1 \pm 0.3)\,\mbox{MeV}$ and
$f_K = (112.4 \pm 0.9) \, \mbox{MeV}$. For the ratios $R_\pi$ and $R_K$ of the
electronic and muonic decay modes, we predict $R_\pi = (1.2354 \pm 0.0002)
\cdot 10^{-4}$ and $R_K = (2.472 \pm 0.001) \cdot 10^{-5}$.
