function calculer(){

	var nb_serveurs = document.getElementById('nb_serveurs').value;
	var temps = document.getElementById('temps').value;
	var salaire = document.getElementById('salaire').value;
	
	if(nb_serveurs == ""){
		nb_serveurs = "1";
		document.getElementById('nb_serveurs').value = 1;
	}
	
	if(temps == ""){
		temps = 30;
		document.getElementById('temps').value = 30;
	}
	
	if(salaire == ""){
		salaire = 1500;
		document.getElementById('salaire').value = 1500;
	}
	
	var actuel = (nb_serveurs * temps / 60 * salaire * 1.5 / 151) * 20;
	var monitoring;
	
	switch(nb_serveurs){
	
		case "1":
			monitoring = 60;
			break;
			
		case "2":
		case "3":
		case "4":
			monitoring = 55;
			break;
			
		case "5":
		case "6":
		case "7":
		case "8":
		case "9":
		case "10":
			monitoring = 50;
			break;
			
		case "11":
		case "12":
		case "13":
		case "14":
		case "15":
		case "16":
		case "17":
		case "18":
		case "19":
			monitoring = 45;
			break;
			
		case "20":
			monitoring = 40;
			break;
	
	}
	
	monitoring = monitoring * nb_serveurs;
	
	var gain = (actuel - monitoring) / actuel * 100;
	
	if(nb_serveurs > 20){
	
		alert("Pour plus de 20 serveurs, nous contacter.");
	
	}else{
	
		document.getElementById('actuel').innerHTML = actuel.toFixed(2) + " €";
		document.getElementById('monitoring').innerHTML = monitoring.toFixed(2) + " €";
		document.getElementById('gain').innerHTML = gain.toFixed(0) + " %";
	
	}

}