the limit arrow: its label too high

My question is an extension of this one. I have the command

\documentclass{article}
\usepackage{amsmath}
\begin{document}
$a_n \xrightarrow{\scriptscriptstyle n\to\infty} 0$
\end{document}


which produces .

How can I alter this command (hopefully in a simple way) to get , i.e. the label is closer to the arrow, so the command doesn't produce ugly additional space between rows.

-

$a_n \xrightarrow{% \raisebox{-2pt}[0pt][0pt]{% \ensuremath{\scriptscriptstyle n\to\infty}}} 0$

If you want it to work more generally, you can throw something together using \mathchoice I presume.
 It does seem to work, thank you :). I'll accept the answer tomorrow, in case there are any more suggestions. – Leon Lampret Sep 23 '11 at 0:17 what do the optional arguments in \raisebox{-2pt}[0pt][0pt]{...} do? – Leon Lampret Sep 23 '11 at 13:44