function get_xmlHttp_object() {
	var xmlHttp=null;
	try { // Firefox, Opera 8.0+, Safari
		xmlHttp=new XMLHttpRequest();
	 }
	catch (e) { // Internet Explorer
		try {
			xmlHttp=new ActiveXObject("Msxml2.xmlHttp");
		 }
		catch (e) {
			xmlHttp=new ActiveXObject("Microsoft.xmlHttp");
		 }
	 }
	return xmlHttp;
 }		

function get_page(page) {
	xmlHttp = get_xmlHttp_object();
	if (xmlHttp==null) {
		alert ("Your browser does not support AJAX!");
		return;
	 }
	var url = page + ".shtml";
	xmlHttp.onreadystatechange = process_page;
	xmlHttp.open("GET",url,true);
	xmlHttp.send(null);
 }

function process_page() { 
	if (xmlHttp.readyState==4)
		document.getElementById("content").innerHTML = xmlHttp.responseText;
 }