Menu Javascript Question

[Princeton]

Currently, the navbar dropdown menu is created in such a manner*:

<td id="navbar_search" class="vbmenu_control"><a href="search.php$session[sessionurl_q]" accesskey="4" rel="nofollow">$vbphrase[search]</a> <script type="text/javascript"> vbmenu_register("navbar_search"); </script></td>

Now, I'm wondering why it isn't done this way:

<td id="navbar_search" class="vbmenu_control"><a href="search.php$session[sessionurl_q]" accesskey="4" rel="nofollow" onclick="vbmenu_register('navbar_search')">$vbphrase[search]</a></td>

I'm guessing that it's done this way* for a reason (eg. browser compatibility). I'm not sure why it's done this way--but, there has to be a reason. Anyone have a clue?

I'm asking because if I don't -- I will keep wondering.