<script type="text/javascript">
function fnCheckScroll() {
var iScrollWidth = oDiv.scrollWidth;
var iOffsetWidth = oDiv.offsetWidth;
var iDifference = iScrollWidth - iOffsetWidth;
alert("Width: " + iOffsetWidth
+ "\nscrollWidth: " + iScrollWidth
+ "\nDifference: " + iDifference);
}
</script>
...
<div id="oDiv" style="overflow: scroll; height= 50px; width= 400px; text-align: left" nowrap>
...
</div>
<button >Check scrollWidth</button>