tai,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
</style>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
<script>
$(function() {
var oldVal = '';
$('body').on('input', '.input-class', function(e){
var newVal = this.value;
var regex = new RegExp(/^\d+(\.\d{0,2})?$/, 'g');
if(newVal && !regex.test(newVal) ){
this.value = oldVal;
}
oldVal = this.value;
});
});
</script>
</head>
<body>
<input type="text" class="input-class">
</body>
</html>