function req( request, user, password, carriera, callback){

	var url = "http://esse3unica.azurewebsites.net/index.php";



	var params = "request=" + request +"&user=" + user +"&password=" + password +"&carriera=" + carriera;



	var http = new XMLHttpRequest();



	http.open("POST", url, true);



	//Send the proper header information along with the request

	http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");



	http.onreadystatechange = function() {//Call a function when the state changes.

    if(http.readyState == 4 && http.status == 200) {

        callback(JSON.parse(http.response));

        //alert(http.responseText);

    	}

	}

	http.send(params);

} //req