You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: Can you please help me to reserve a plane ticket from Oakland to Los Angeles?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: Thank you. My travel dates are Apr 01 and Apr 03.

ASSISTANT: Can I know your airport codes too?

USER: The source and destination airport codes are OAK and LAX.

ASSISTANT: Can I know your name please?

USER: I am Elizabeth Davis.

ASSISTANT: Can I know your preferences?

USER: My preferred number of connections in between the journey should be at least one.

ASSISTANT: Sorry, there are no flights found in our database.

USER: It's ok, not an issue with that. Thank you for searching the flights.

ASSISTANT: Thank you for reaching us.

USER: You are welcome.