var pos=0;
var tmo=0;
var howtall=0;

window.onload=function() {scrollItprep();}

function scrollItprep() {
        // find height of image pile to reset scroll later
howtall=(0-(document.getElementById('navcontents').offsetHeight));
        // replicate html of image pile into repeathtml (to appear to seamlessly loop)
document.getElementById('repeathtml').innerHTML='<ul id="navcontents">'+document.getElementById('navcontents').innerHTML+'</ul>';
scrollIt();
}

function scrollIt() {
document.getElementById('navscroll').style.top= pos +'px';
pos--;

if (pos==howtall)
	{pos=0;clearTimeout(tmo);}
tmo=setTimeout('scrollIt()',20);
 }