var fileNum = 19;
var URLTestimonialPath = 'http://' + location.host + '/testimonial/';

function getTestimonial() {
  var randomNum = Math.random() * fileNum + 1; // add 1 to increment the base of zero
  var randomFile = URLTestimonialPath + Math.floor(randomNum) + '.htm';
  AjaxRequest.get(
    {
      'url':randomFile,
      'onSuccess':function(req){ document.getElementById('TestimonialDiv').innerHTML = (req.responseText); }
    }
  );
}