Menu Desplegable hacia abajo con js

[sandymiau]

Código:

<style>
/*** ESSENTIAL STYLES ***/
.sf-menu, .sf-menu * {margin:	0; padding:0; list-style:none;}
.sf-menu {line-height:	1.0;}
.sf-menu ul {position:absolute; top:-999em; width:	10em; /* left offset of submenus need to match (see below) */}
.sf-menu ul li {width:100%;}
.sf-menu li:hover {visibility:	inherit; /* fixes IE7 'sticky bug' */}
.sf-menu li {float:	left; position:		relative;}
.sf-menu a {display:	block;position:		relative;}
.sf-menu li:hover ul,.sf-menu li.sfHover ul {left:0; top:2.5em; /* match top ul list item height */z-index:99;}
ul.sf-menu li:hover li ul, ul.sf-menu li.sfHover li ul {top:-999em; }
ul.sf-menu li li:hover ul, ul.sf-menu li li.sfHover ul {left:10em; /* match ul width */
top:0;}
ul.sf-menu li li:hover li ul, ul.sf-menu li li.sfHover li ul {top:-999em;}
ul.sf-menu li li li:hover ul,ul.sf-menu li li li.sfHover ul {left:10em; /* match ul width */ top:0;}
/*** DEMO SKIN ***/
.sf-menu {float:left;margin-bottom:1em;}
.sf-menu a {border-left:1px solid #fff; border-top:1px solid #CFDEFF; padding:	.75em 1em;text-decoration:none;}
.sf-menu a, .sf-menu a:visited  { /* visited pseudo selector so IE6 applies text colour*/color:#13a;}
.sf-menu li {background:		#BDD2FF;}
.sf-menu li li {background:		#AABDE6;}
.sf-menu li li li {background:		#9AAEDB;}
.sf-menu li:hover, .sf-menu li.sfHover,.sf-menu a:focus, .sf-menu a:hover, .sf-menu a:active {background:#CFDEFF;outline:		0;}

/*** arrows **/
.sf-menu a.sf-with-ul {padding-right: 	2.25em;min-width:1px; /* trigger IE7 hasLayout so spans position accurately */}
.sf-sub-indicator {position:absolute; display:block; right:.75em; top:1.05em; /* IE6 only */width:10px; height:10px; text-indent:-999em; overflow:hidden; background:url('../images/arrows-ffffff.png') no-repeat -10px -100px; /* 8-bit indexed alpha png. IE6 gets solid image only */}
a > .sf-sub-indicator {  /* give all except IE6 the correct values */top: 	.8em;
background-position: 0 -100px; /* use translucent arrow for modern browsers*/}
/* apply hovers to modern browsers */a:focus > .sf-sub-indicator,a:hover > .sf-sub-indicator, a:active > .sf-sub-indicator, li:hover > a > .sf-sub-indicator, li.sfHover > a > .sf-sub-indicator {background-position: -10px -100px; /* arrow hovers for modern browsers*/}
/* point right for anchors in subs */ .sf-menu ul .sf-sub-indicator { background-position:  -10px 0; }
.sf-menu ul a > .sf-sub-indicator { background-position:  0 0; }
/* apply hovers to modern browsers */ .sf-menu ul a:focus > .sf-sub-indicator, .sf-menu ul a:hover > .sf-sub-indicator, .sf-menu ul a:active > .sf-sub-indicator,
.sf-menu ul li:hover > a > .sf-sub-indicator, .sf-menu ul li.sfHover > a > .sf-sub-indicator {background-position: -10px 0; /* arrow hovers for modern browsers*/}
/*** shadows for all but IE6 ***/
.sf-shadow ul {background:	url('../images/shadow.png') no-repeat bottom right;
padding: 0 8px 9px 0;-moz-border-radius-bottomleft: 17px; -moz-border-radius-topright: 17px; -webkit-border-top-right-radius: 17px; -webkit-border-bottom-left-radius: 17px;}
.sf-shadow ul.sf-shadow-off {background: transparent; }
</style>

Solo haz los cambios necesarios dentro de las etiquetas <li> de acuerdo a tus necesidades.