i stuck in if condition in javascript using angular controller

enter code here
// I am stuck at if condition in angular controller
    app.controller("HomeController", function($scope, $cookies, $location, $http, $timeout, UserDetails){
    $scope.title = "fill the form to create your cv";
    $scope.step1 = true;
    $scope.step2 = false;
    $scope.step3 = false;
    $scope.step4 = false;
    $scope.submitForm1 = function(){
    alert(this.objective);
    alert(this.fullName);
    alert(this.email);
    alert(this.phoneNo);
//this if condition is not working....
    if(this.fullName == "" || this.email == "" || this.phoneNo == "" || this.objective == ""){
    $scope.title = "all fields are required";
    alert("all fields required");
    return false;
    }else{
    alert("not empty");
    }
    } 
    });