var xhr = null; 
function getXhr(){
	if(window.XMLHttpRequest)
		{
		xhr = new XMLHttpRequest();	
		}
	else if(window.ActiveXObject)
		{ 
		try{
			xhr = new ActiveXObject("Msxml2.XMLHTTP");
			} catch (e){
				xhr = new ActiveXObject("Microsoft.XMLHTTP");
				}
		}
	else 
		{
		alert("Votre navigateur ne supporte pas les objets XMLHTTPRequest..."); 
		xhr = false; 
		} 
	}

function modifElementAjax(idElement,lienPage){
	getXhr();
	xhr.open("GET",lienPage,true);
	xhr.onreadystatechange = function(){
		if(xhr.readyState == 4 && xhr.status == 200)
			{
			document.getElementById(idElement).innerHTML=xhr.responseText;
			}
		}
	xhr.send(null);
}