Untitled

<!DOCTYPE html>
<html>
  <head>
    <script type="text/javascript">
      var greet = function(callback) {
        var todaysGreeting = "Hello";
        callback(todaysGreeting);
      }

      a = greet(function(name){
        return name;
      });
    function Greeter (name) {
        this.name = name;
        this.run = getGreetInfo;
    }

    function getGreetInfo() {
        return ( a + this.name);
    }

    alert((new Greeter("world!")).run());
    alert((new Greeter("universe!")).run());

    </script>
  </head>
  <body>
  </body>
</html>