[texhax] help

[Raffaele Cotza]

Haw I can begin tu use PSRricks on my MacBook Air ?
I try this :
\pstVerb{ 1234321 srand }
\begin{pspicture}[showgrid](-2,-2)(2,2)
\psframe*[linecolor=blue,opacity=!Rand](2,2)
\psframe*[linecolor=red,opacity=!Rand](-1,-1)
  (1,1)
\psframe*[linecolor=green,opacity=!Rand](-2,-2)
  (0,0)
\end{pspicture}

and I obtain no result
Thank you
Raffaele