hmmmm virker ikke!!

Hvorfor virker dette ikke...

<script>
function menu(minaction,minmenu)
{
if(minaction==\"open\")
{
document.all[\"menu\"+minmenu].style.visibility = \"visible\";
}
else if(minaction==\"close\")
{
document.all[\"menu\"+minmenu].style.visibility = \"hidden\";
}
}
</Script>

<a href=\"#\" onmouseover=\"menu(open,1);\" onmouseout=\"menu(close,1);\">Menu 1</a>
<div id=\"menu1\" onmouseover=\"menu(0,1)\" onmouseout=\"menu(1,1)\" id=\"menu1\" style=\"visibility:hidden;\">
WussarP?
</div>