inputChange.html

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=0, minimum-scale=1.0, maximum-scale=1.0">
<meta name="apple-mobile-web-app-capable" content="yes">
<meta name="apple-mobile-web-app-status-bar-style" content="black">
<title>inputChange</title>
<script src="util.js"></script>
<script>
window.onload = function () {
    var change = XSUtil.inputChange;
    change('#demo', function () {
        document.querySelector('.demo').value = this.value;
    });
    change('.demo', function () {
        document.querySelector('#demo').value = this.value;
    });
}
</script>
</head>
<body>
<input type="text" id="demo" />
<input type="text" class="demo" />
</body>
</html>