<script type="text/javascript">
      var add = function(firstName, lastName) {
        this.name = firstName + " " + lastName;
      };

      var small = {
        name: ""
      };
      var capital = {
        name: ""
      };

      add.call(small, "enjoy", "water"); // enjoy water
      add.apply(capital, ["ENJOY", "WATER"]); // ENJOY WATER

      console.log(small.name); // enjoy water
      console.log(capital.name); // ENJOY WATER
</script>