It's only AJAX if you pull in the data from the network as needed. If you just
hide the data then it's good old "DHTML," which means Javascript controlling CSS.
HTML Code:
<html><head>
<script language="javascript"><!--
function toggleshow(elemid) {
if (!document.getElementById) return; // browser check
var elem= document.getElementById(elemid);
if (!elem) return;
var s= elem.style;
if (!s) return;
s.display= s.display=='none' ? 'block' : 'none';
return true;
}
//--></script>
</head><body>
Intro text...
<a href="moretext.htm" onClick="return !toggleshow('extratext')">
more text</a>
<div id="extratext" style="display: none;">
...more text to read.
</div>
</body></html>
You'd have to make a "moretext.htm" page as a fallback for those with Javascript disabled, old browsers, etc.