What is the theme in The Voice on the Radio by Caroline B. Cooney?

Overcoming fear is an important theme in the book. In "Whatever Happened to Janie?" Janie is forced to face her fears on several levels. In order to put the events in motion, Janie had to face her first fear, confronting the information she found on the milk carton. It takes several weeks, but Janie faces the fact that her parents are not her parents, which doesn't change how she feels about them. Originally, Janie had just thought that she could send a message to her birth parents, letting them know that she is okay.