function checkDispo(){
	var xhr_object = null; 
	if(window.XMLHttpRequest){ 
	   xhr_object = new XMLHttpRequest();
	   }
	else if(window.ActiveXObject){
	   xhr_object = new ActiveXObject("Microsoft.XMLHTTP");
	   }
	else {
   alert("Votre navigateur ne supporte pas les objets XMLHTTPRequest..."); 
	   return; 
	}
		 
	var method   = "POST"; 
	var filename = "dispo.php3"; 
	var maDestination = document.getElementById('maDestination').value;
	var maFormule = document.getElementById('maFormule').value;
	var monProfil = document.getElementById('monProfil').value; 
	var data     = null; 
	 
	if(maDestination != "" && maFormule != "" && monProfil != "") {
	   data = "maDestination="+maDestination+"&maFormule="+maFormule+"&monProfil="+monProfil; 
	}
	if(method == "GET" && data != null) { 
	   filename += "?"+data; 
	   data      = null; 
	} 
	 
	xhr_object.open(method, filename, true); 
	 
	xhr_object.onreadystatechange = function() { 
	   if(xhr_object.readyState == 4) { 
	      var tmp = xhr_object.responseText;

	      document.getElementById('searchlegend').title=document.getElementById('searchlegend').innerHTML+' - Des destinations correspondent à votre sélection';
 
	         if(tmp == "1"){
	      document.getElementById('searchavailable').style.visibility="visible";	         	
	         } else {
	      document.getElementById('searchavailable').style.visibility="hidden";
	      	 }

	   } 
	} 
	 
	if(method == "POST"){
	xhr_object.setRequestHeader("Content-type", "application/x-www-form-urlencoded"); 
	xhr_object.send(data);
	}
}