<div id="pb_all">  
       <a href="javascript://" onclick="progressBar();">  
        Скачать  
       </a>  
</div>

<script type="text/javascript">       
function progressBar(set) {  
       set = set || {};  
       document.getElementById('pb_all').innerHTML  
= '<div id="ot" style="width:' + (set.outW || 100) + 'px;height:' +  
(set.outH || 20) + 'px;' + (set.outB || 'border:1px solid #79a0c1') +  
';"><div id="pb" style="background:' + (set.inB || '#e6e6fa') +  
';width:0px;height:' + (set.outH || 20) +  
'px;"></div></div>';  
       var bar = document.getElementById('pb');  
       x = setInterval(function () {  
        if (parseInt(bar.style.width) < (set.outW || 100)) {  
         bar.style.width = parseInt(bar.style.width) + (set.step || 1) + 'px';  
        } else {  
         clearInterval(x);  
         location.href = '$FILE_URL$';  
        }  
       },  
       1000 / (set.speed || 2))  
}  
</script>

progressBar({step:1, speed:30, outW:300, inB: '#000000'});