Unable to add data into firebase realtime database using javascript

var config = {
apiKey: "A**********************kBs",
authDomain: "the**********.firebaseapp.com",
databaseURL: "https://***********.firebaseio.com",
projectId: "the-o***********nette",
storageBucket: "the***********.appspot.com",
messagingSenderId: "6***********6"
  };
  firebase.initializeApp(config);

$("#register").click(
  function(){

var email=$("#regEmail").val();
var password=$("#regPass").val();
var fname=$("#regfName").val();
var lname=$("#reglName").val();

  firebase.auth().createUserWithEmailAndPassword(email, 
password).catch(function(error) {
  // Handle Errors here.
  var errorCode = error.code;
  var errorMessage = error.message;
  alert(errorMessage)
  // ...
    });
    alert( "you have successfully registered");
    // Get a reference to the database service
    var database = firebase.database();
    var userId = firebase.auth().currentUser;


  firebase.database().ref('users/' + userId).set({
fname: fname,
lname: lname,
email: email,

  }).catch(function(error){
  var errormsg=error.message;
  console.log(errormsg);
  });

  }
);

The createuserwithemailandpassword is working properly. But I am not able to add anything into the database. No error log is reported. The var is mentioned in the HTML file. Let me know if anything else is needed. thanks!