var pause=10;
var pause_off=1.5;
var step=10;
var opac=0;
var timer;
var count=0;

function fadeTxt(){
fadeEl=document.getElementById('promo');
fadeEl.firstChild.nodeValue=arr[count];
opac+=step;

if(fadeEl.filters){
fadeEl.style.filter='alpha(opacity='+opac+')';
}
else{
fadeEl.style.opacity=(opac/100)-0.01;
}

timer=setTimeout("fadeTxt()",10)

if(opac>=50){
clearTimeout(timer);
opac=50;
step=-step;
setTimeout("fadeTxt()",pause*1000);
return;
}

if(opac<0){
clearTimeout(timer);
step=-step;
count++;
if(count==arr.length){
count=0;
}
setTimeout("fadeTxt()",pause_off*1000);
}
}