function createInstance()
{
	var req = null;
	if (window.XMLHttpRequest)
	{
		req = new XMLHttpRequest();
	} 
	else if (window.ActiveXObject) 
	{
		try {
			req = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e)
		{
			try {
				req = new ActiveXObject("Microsoft.XMLHTTP");
			} catch (e) 
			{
				alert("XHR not created");
			}
		}
	}
	return req;
};


function storing(data, element)
{
	element.innerHTML = data;
}



function submitForm(element, message, limit)
{
	var req =  createInstance();
	var data = "message=" + message + "&limit=" + limit;

	req.onreadystatechange = function()
	{ 
		if(req.readyState == 4)
		{
			if(req.status == 200)
			{
				storing(req.responseText, element);
				rafraichir(element, limit);
			}
			else
			{
				alert("Erreur " + req.status + " : " + req.statusText);
			}
		}
	};
	
	req.open("POST", "tchat_post.php", true);
	req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
	req.send(data);
}

function rafraichir(element, limit)
{
	var req =  createInstance();

	req.onreadystatechange = function()
	{ 
		if(req.readyState == 4)
		{
			if(req.status == 200)
			{
				storing(req.responseText, element);	
			}	
			else	
			{
				alert("Erreur " + req.status + " : " + req.statusText);
			}	
		} 
	}; 
	req.open("GET", "tchat_get.php?limit="+limit, true);
	req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
	req.send(null);
}