Código PHP:
<script language="javascript">
var slideMenu=function(){
var sp,st,t,m,sa,l,w,sw,ot;
return{
build:function(sm,sw,mt,s,sl,h){
sp=s; st=sw; t=mt;
m=document.getElementById(sm);
sa=m.getElementsByTagName('li');
l=sa.length; w=m.offsetWidth; sw=w/l;
ot=Math.floor((w-st)/(l-1)); var i=0;
for(i;i<l;i++){s=sa[i]; s.style.width=sw+'px'; this.timer(s)}
if(sl!=null){m.timer=setInterval(function(){slideMenu.slide(sa[sl-1])},t)}
},
timer:function(s){s.onmouseover=function(){clearInterval(m.timer);m.timer=setInterval(function(){slideMenu.slide(s)},t)}},
slide:function(s){
var cw=parseInt(s.style.width,'10');
if(cw<st){
var owt=0; var i=0;
for(i;i<l;i++){
if(sa[i]!=s){
var o,ow; var oi=0; o=sa[i]; ow=parseInt(o.style.width,'10');
if(ow>ot){oi=Math.floor((ow-ot)/sp); oi=(oi>0)?oi:1; o.style.width=(ow-oi)+'px'}
owt=owt+(ow-oi)}}
s.style.width=(w-owt)+'px';
}else{clearInterval(m.timer)}
}
};
}();
</script>