var movies = {
   movie1: {
    movieName: "Toy Story 2",
    review: "Great story. Mean Prospector.",
        },
   movie2: {
    movieName: "Finding Nemo",
    review: "Cool animation, and funny turtles.",
        },
   movie3: {
    movieName: "The Lion King",
    review: "Great songs.",
        },
};
for(var index in movies){
 console.log(index); //movie1, movie2, movie3
}
var getReview = function (movie) {
  for(var index in movies){
      console.log(index); //movie1, movie1, movie1
    if(movies[index].movieName === movie){
      return movies[index].review;
        }else return "I don't know";
      }
};

console.log(getReview("Toy Story 2")); //Great story, Mean Prospector

console.log(getReview("The Lion King")); //I don't know

console.log(getReview("Finding Nemo")); //I don't know