Hola..
Aqui esta el codigo para qye funcione tal como quieres :D
////NO NEED TO EDIT BELOW THIS LINE////////////
var iedom=document.all||document.getElementById
if (iedom)
document.write('<span id="temp" style="visibility:hidden;position:absolute;top:-100;left:-1000">'+menucontents+'</span>')
var actualwidth=''
var cross_scroll, ns_scroll
var loadedyes=0
function fillup(){
if (iedom){
cross_scroll=document.getElementById? document.getElementById("test2") : document.all.test2
cross_scroll.innerHTML=menucontents
actualwidth=document.all? cross_scroll.offsetWidth : document.getElementById("temp").offsetWidth
}
else if (document.layers){
ns_scroll=document.ns_scrollmenu.document.ns_scrol lmenu2
ns_scroll.document.write(menucontents)
ns_scroll.document.close()
actualwidth=ns_scroll.document.width
}
loadedyes=1
}
window.onload=fillup
function moveleft(){
if (loadedyes){
if (iedom&&parseInt(cross_scroll.style.left)>(menuwid th-actualwidth)){
cross_scroll.style.left=parseInt(cross_scroll.styl e.left)-scrollspeed
}
else if (document.layers&&ns_scroll.left>(menuwidth-actualwidth))
ns_scroll.left-=scrollspeed
}
lefttime=setTimeout("moveleft()",50)
}
function moveright(){
if (loadedyes){
if (iedom&&parseInt(cross_scroll.style.left)<0)
cross_scroll.style.left=parseInt(cross_scroll.styl e.left)+scrollspeed
else if (document.layers&&ns_scroll.left<0)
ns_scroll.left+=scrollspeed
}
righttime=setTimeout("moveright()",50)
}
if (iedom||document.layers){
with (document){
write('<table border="0" cellspacing="0" cellpadding="0">')
write('<td valign="middle"><a class="links" href=#" onMouseover="moveright()" onMouseout="clearTimeout(righttime)"><img src="'+goleftimage+'"border=0></a> </td>')
write('<td valign="top">')
if (iedom){
write('<div style="position:relative;width:'+menuwidth+';">')
write('<div style="position:absolute;width:'+menuwidth+';heigh t:'+menuheight+';overflow:hidden;">')
write('<div id="test2" style="position:absolute;left:0;top:0">')
write('</div></div></div>')
}
else if (document.layers){
write('<ilayer width='+menuwidth+' height='+menuheight+' name="ns_scrollmenu">')
write('<layer name="ns_scrollmenu2" left=0 top=0></layer></ilayer>')
}
write('</td>')
write('<td valign="middle"> <a class="links" href="#" onMouseover="moveleft()" onMouseout="clearTimeout(lefttime)">')
write('<img src="'+gorightimage+'"border=0></a>')
write('</td></table>')
}
}
</script>
Saludos!