Who is the host of the program?

Billy: Good evening and welcome to "This Is Your Life". This is Billy Smith speaking. We are waiting for the subject of tonight’s program.  He is one of the world’s leading actors, and he thinks he is coming here to take part in a discussion program... I can hear him now.., yes, here he is ! James Douglas... This is your life ! James: Oh, no... I don’t believe it! Not me...
Billy: Yes, it is you! Now come over here and sit down. James, you were one of four children, and your father was a bus driver. Of course, your name was then Jason White.