function ajax_open_close(ptr, id_bloc, url) {

	// Récupération des champs :
	var data="id_bloc="+id_bloc;

	// Transfert Ajax :
	var xhr_object = null;   
	if(window.XMLHttpRequest) xhr_object = new XMLHttpRequest();   
	else if(window.ActiveXObject) xhr_object = new ActiveXObject("Microsoft.XMLHTTP");   
	else { alert("Error XMLHttpRequest"); return; }     

	xhr_object.open("POST", url, true);   
	xhr_object.onreadystatechange = function() { if(xhr_object.readyState == 4) eval(xhr_object.responseText); }   
	xhr_object.setRequestHeader("Content-type", "application/x-www-form-urlencoded");   
	xhr_object.send(data);  
}