  Let $\Omega=\{r<0\}\subset\mathbb C^2$, with $r$ plurisubharmonic on
$b\Omega=\{r=0\}$. Let $\rho$ be another defining function for $\Omega$. A
formula for the determinant of the complex Hessian of $\rho$ in terms of $r$ is
computed. This formula is used to give necessary and sufficient conditions that
make $\rho$ (locally) plurisubharmonic.
