<link rel="stylesheet" href="https://apps.bdimg.com/libs/jquerymobile/1.4.2/jquery.mobile.min.css">
<script src="https://apps.bdimg.com/libs/jquery/1.10.2/jquery.min.js"></script>
<script src="https://apps.bdimg.com/libs/jquerymobile/1.4.2/jquery.mobile.min.js"></script>
$(document).on("pagebeforeshow","#pagetwo",function(event,data){
alert(data.prevPage.attr("id") +" is about to be hidden");
$(document).on("pagebeforeshow","#pagetwo",function(){
alert("pagetwo is about to be shown");
<div data-role="page" id="pageone">