To implement this you will need to:
1. Every time your page loads a "init()" function will load.
2. Define a div named "loading" right after section.
<div id="loading" style="position:absolute; width:100%; text-align:center; top:300px;"> <img src="loading.gif" border=0></div>
The loading.gif image should be an animated gif that suggests that the page is still loading.