  Given an Orlicz function $M$, we show which random variables $\xi_i$,
$i=1,...,n$ generate the associated Orlicz norm, i.e., which random variables
yield $\mathbb{E} \max\limits_{1\leq i \leq n}|x_i\xi_i| \sim
\norm{(x_i)_{i=1}^n}_M$. As a corollary we obtain a representation for the
distribution function in terms of $M$ and $M'$ which can be easily applied to
many examples of interest.
