function conserver(keyword) {

	var xhr_object = null;
	
	if(window.XMLHttpRequest) // Firefox
	   xhr_object = new XMLHttpRequest();
	else if(window.ActiveXObject) // Internet Explorer
	   xhr_object = new ActiveXObject("Microsoft.XMLHTTP");
	else { // XMLHttpRequest non supporté par le navigateur
	   alert("Votre navigateur ne supporte pas les objets XMLHTTPRequest...");
	   return;
	}

	xhr_object.open("GET", "conserv_keyword.php?keyword="+keyword, true);

	xhr_object.onreadystatechange = function() {
	   if(xhr_object.readyState == 4) echo "ok";
	}

	xhr_object.send(null);

}