temp.txt

        //Hide the Content
        document.getElementById('UserDetails').style.display="none";
        document.getElementById('confirmation').style.display="none";
        document.getElementById('logout').style.display="none";
        document.getElementById('updateData').style.display="none";

        // Initialize Firebase
        var config = {
            ***
        };
        firebase.initializeApp(config);

        //Call Events
        document.getElementById('login').addEventListener('click',loginUser);
        document.getElementById('submit').addEventListener('click',addData);
        document.getElementById('logout').addEventListener('click',logoutUser);


        //Google Sign In Provider
        var provider = new firebase.auth.GoogleAuthProvider();
        
        //Call Functions
        function loginUser(){
            firebase.auth().signInWithPopup(provider).then(function(result) {
                  var token = result.credential.accessToken;
                  var user = result.user;
                  console.log(user);     
            }).catch(function(error) {
              var errorCode = error.code;
              var errorMessage = error.message;
              var email = error.email;
              var credential = error.credential;
            });
        }

        function logoutUser(){
            firebase.auth().signOut().then(function() {
                // Sign-out successful.
                document.getElementById('logout').style.display="none";
                document.getElementById('login').style.display="block";
                document.getElementById('UserDetails').style.display="none";
                document.getElementById('updateData').style.display="none";
            }).catch(function(error) {
            // An error happened.
            });
        }


        var email;
        var uid;
        console.log("User Email "+email);
        
        function addData(){
            if(email){
                var name=document.getElementById('name').value;
                var mobile=document.getElementById('mobile').value;
                var organization=document.getElementById('organization').value;
                var designation=document.getElementById('designation').value;
                var why=document.getElementById('why').value;
                
                var data={
                    name:name,
                    email:email,
                    mobile:mobile,
                    org:organization,
                    designation:designation,
                    why:why,
                    timestamp:Date(),
                    uid:uid
                }
                
                firebase.database().ref('IOAttendees/'+uid).set(data).then(()=>{
                    alert("User SuccessFully Registered");
                    document.getElementById('UserInput').innerHTML="Thank you Filling this Form";
                    document.getElementById('confirmation').style.display="block";


                })
                console.log(email);
            }
            else{
                alert("you need to Login with Google");
                //document.getElementById('userDetailSection').innerHTML="Thank you Filling this Form";
            }
          
        }


         firebase.auth().onAuthStateChanged(function(user) {
            if (user) {
                var displayName = user.displayName;
                email = user.email;
                var emailVerified = user.emailVerified;
                var photoURL = user.photoURL;
                var isAnonymous = user.isAnonymous;
                uid = user.uid;
                var providerData = user.providerData;
                
                console.log(email);

                document.getElementById('SignInMsg').innerHTML="<b style='color:blue'>"+displayName+"</b> Successfully Logged In with : <b style='color:blue'>"+email+"</b>";

                document.getElementById('logout').style.display="block";
                document.getElementById('login').style.display="none";
                
                
                
                firebase.database().ref('IOAttendees/'+uid).once('value',(snap)=>{
                    if(snap.val()){
                        document.getElementById('UserDetails').style.display="none";
                        document.getElementById('updateData').style.display="block";
                    }
                    else{
                        document.getElementById('UserDetails').style.display="block";
                    }
                })
                // ...
            } else {
                // User is signed out.
                // ...
                document.getElementById('UserDetails').style.display="none";
                console.log("err");
                document.getElementById('SignInMsg').innerHTML="You need to sign in with a Google account or a Gmail address to register for this event.";
            }
        });