function creerRequete() {
	
	var xhr = null;
	
	if(window.XMLHttpRequest || window.ActiveXObject) {
	        if(window.XMLHttpRequest) {
	                xhr = new XMLHttpRequest(); 
	        }
	        else { // Internet Explorer <7
	                try {
	                        xhr = new ActiveXObject("Msxml2.XMLHTTP");
	                } catch(e) {
	                        xhr = new ActiveXObject("Microsoft.XMLHTTP");
	                }
	        }
	}
	else {
	        alert("Votre navigateur ne supporte pas l'objet XMLHTTPRequest...");
	        return;
	}
	
	return xhr;
}