For rounding off numbers make use of Math.round and Math.pow .. .check the below sample:
<html>
<head>
<script language="javascript">
function fnRound()
{
var formField = document.frmTest.txtValue;
var roundedValue = Math.round(formField.value*Math.pow(10,1))/Math.pow(10,1);
formField.value = roundedValue;
}
</script>
</head>
<body>
<form name="frmTest">
<input type="text" name="txtValue">
<input type="button" value="Round" onClick="fnRound();">
</form>
</body>
</html>
Best Regards
Vadivel
MVP ASP/ASP.NET
http://vadivel.thinkingms.com