<span id="linkPlace"><span class="buttona">Скачать через: <span id='timeNumer'>0</span> сек.</span></span>  
<script>  
var timerFIG = 10;  
document.all.timeNumer.innerHTML = timerFIG;  
var timer = setInterval("startTimer()",1000);  
function startTimer() {  
if(timerFIG !== 1) {  
timerFIG--;  
document.all.timeNumer.innerHTML = timerFIG; } else {  
clearInterval(timer);  
document.all.linkPlace.innerHTML = "<span class=\"buttonb\" onclick=\"window.open('$FILE_DIRECT_URL$')\">Скачать</span>"; } }  
</script>  
  
<span class="buttonb" onclick="window.open('$FILE_DIRECT_URL$')">Скачать</span>  

.buttona {border: 1px solid #799DC4; background: #ffcece; padding : 5px; text-align: left; color: #0D2938;}  
.buttonb {border: 1px solid #799DC4; background: #cccccc; padding : 5px; text-align: left; color: #0D2938;}