How to create the "More" link button to display rest of the text

JavaScript
8

oh okay
but i saw this code but it don’t work for firefox
<script language=“JavaScript”>
function truncate() {
var len = 100;
var p = document.getElementById(‘truncateMe’);
if (p) {
var trunc = p.innerHTML;
if (trunc.length > len) {

  trunc = trunc.substring(0, len);
  trunc = trunc.replace(/\\w+$/, '');

  /* Add an ellipses to the end and make it a link that expands
     the paragraph back to its original size */
  trunc += '&lt;a href="#" ' +
    'onclick="this.parentNode.innerHTML=' +
    'unescape(\\''+escape(p.innerHTML)+'\\');return false;"&gt;' +
    '&lt;span style="font-size: 10px;"&gt;[ more ... ]&lt;/span&gt;&lt;\\/a&gt;';
  p.innerHTML = trunc;
  
  
  
  }

}
}
</script>