var config = {

    apiKey: "AIzaSyCvpYQu44zmRXA0XQkcxEuakyytRsnWXSc",

    authDomain: "stackoverflow.firebaseapp.com",

    databaseURL: "https://stackoverflow.firebaseio.com",

    storageBucket: "project-8080059325282098184.appspot.com",

  };

  //firebase.database.enableLogging(true);

  firebase.initializeApp(config);

​

​

var ref = firebase.database().ref("39062400");

​

// quick check to see if writing works when you use a double //

ref.child('child//sub').set('value');