det kan man gøre på mange måder - eksempelvis:
<html>
<head><title></title>
</head>
<body>
<script type="text/javascript">
function getInterval(intervals,number) {
for ( var c = 1; c < intervals.length; c++ ) {
if ( number >= intervals[c-1] && number <
intervals[c] ) return intervals[c-1] + '-' + intervals[c];
}
return "out of range";
}
</script>
<input type="text"><button
onclick="alert(getInterval([0,500,1000,1500,2000,2500,3000,3500,4000],this.parentNode.getElementsByTagName('input')[0].value));">Se
interval</button>
</body>
</html>
--
Christian Hansen
http://www.resource-it.dk/