addFuelToToyota.js

var toyota = 
{
  make: "Toyota",
  model: "Corolla",
  year: 2015,
  color: "white",
  passengers: 5,
  convertibe: false,
  mileage: 58000,
  started: false,
  fuel: 0,
  start: function() 
  {
  this.started = true;
  },
  stop: function() 
  {
  this.started = false;
  },
  drive: function() 
  {
    if (this.started) 
    {
    alert("Brooom Brooom");
    }
    else 
    {
    alert("you need to start the engine first!");
    }
  },
  addFuel: function () 
  {
  this.fuel = prompt("Add fuel to the car", ); 
  },
  checkFuel: function ()
  {
    if (this.fuel === 0) 
    {
    alert("You need to add fuel!");
    }
  }
};
toyota.checkFuel();
toyota.addFuel();
toyota.start();
toyota.drive();