Getting the User Name and Login Name of the currently Logged User using ECMA Script

var context = ""; 
var web = ""; 
var currentUser = ""; 
    function getLoggedUser() { 
        context = new SP.ClientContext.get_current(); 
        web = context.get_web(); 
        currentUser = web.get_currentUser(); 
         currentUser.retrieve(); 
        context.load(web); 
        context.executeQueryAsync(Function.createDelegate(this, this.onSuccessMethod), Function.createDelegate(this, this.onFailureMethod)); 
    } 
    function onSuccessMethod(sender, args) { 
        var strCurrentLoggedUser = web.get_currentUser(); 
        alert('User name:' + strCurrentLoggedUser .get_title() + '\n Login Name:' + strCurrentLoggedUser .get_loginName()); 
    } 
    function onFailureMethod(sender, args) { 
        alert('request failed ' + args.get_message() + '\n' + args.get_stackTrace()); 
    }
   
    ExecuteOrDelayUntilScriptLoaded(getLoggedUser, "sp.js");