$(document).bind(window, 'load', ad_728x90, false);
function ad_728x90(){
  var url    = '/fra_ad_728x90.php';
	var pars   = '';
	var target = 'div-ad_728x90';
	var myAjax = new Ajax.Updater(target, url, {	method: 'get',	parameters: pars});
}