JavaScript Progress Bar

<table align="center"><tr><td>
<div id="showbar" style="font-size:8pt;padding:2px;border:solid black 1px;visibility:hidden">
<span id="progress1">&nbsp; &nbsp;</span>
<span id="progress2">&nbsp; &nbsp;</span>
<span id="progress3">&nbsp; &nbsp;</span>
<span id="progress4">&nbsp; &nbsp;</span>
<span id="progress5">&nbsp; &nbsp;</span>
<span id="progress6">&nbsp; &nbsp;</span>
<span id="progress7">&nbsp; &nbsp;</span>
<span id="progress8">&nbsp; &nbsp;</span>
<span id="progress9">&nbsp; &nbsp;</span>
</div>
</td></tr></table>
<script language="javascript">
var progressEnd = 9; // set to number of progress <span>'s.
var progressColor = 'blue'; // set to progress bar color
var progressInterval = 1000; // set to time between updates (milli-seconds)

var progressAt = progressEnd;
var progressTimer;
function progress_clear() {
for (var i = 1; i <= progressEnd; i++) document.getElementById('progress'+i).style.backgroundColor = 'transparent';
progressAt = 0;
}
function progress_update() {
document.getElementById('showbar').style.visibility = 'visible';
progressAt++;
if (progressAt > progressEnd) progress_clear();
else document.getElementById('progress'+progressAt).style.backgroundColor = progressColor;
progressTimer = setTimeout('progress_update()',progressInterval);
}
function progress_stop() {
clearTimeout(progressTimer);
progress_clear();
document.getElementById('showbar').style.visibility = 'hidden';
}
//progress_update(); // start progress bar

</script>

<input type="button" name="b1" value="Start Progress Bar" onClick="progress_update()">

<input type="button" name="b2" value="Stop Progress Bar" onClick="progress_stop()">