var request;

function createRequest() 
{
	try {
	 request = new XMLHttpRequest();
	} catch (trymicrosoft) {
	 try {
		request = new ActiveXObject("Msxml2.XMLHTTP");
	 } catch (othermicrosoft) {
		try {
			request = new ActiveXObject("Microsoft.XMLHTTP");
		} catch (failed) {
			request = false;
		}
	 }
	}

	if (!request)
	 alert("Error initializing XMLHttpRequest!");
	return request;
}

function getPage(filename) 
{
//	alert(filename);
	createRequest();
	var url = "functions/getpage.php";
	request.open("POST", url, true);
	request.setRequestHeader('Content-Type','application/x-www-form-urlencoded'); 
	request.onreadystatechange = updatePage;
	request.send("filename="+filename);
}
function updatePage() 
{
	if (request.readyState == 4) {
	 if (request.status == 200) {
		var response = request.responseText;
		main.innerHTML = response;
		
	 } else
		alert("status is " + request.status);
	}
}