What is wrong here, index.php
<div id="divM"></div>
<script src="jquery-1.9.1.min.js"></script>
<script src="index.js"></script>
index.js
$("#select01").change(function(){
var a = $(this).val() + ".php";
$("#divM").load(a);
});
So, a page is loaded inside divM
and select03
is inside the loaded page.
index.js
$("#select03").on("change", function(){
alert ("323"); // nothing happens here !
});