You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Can you please help me to book a flight from PHL to OAK?

ASSISTANT: Let me know your travelling dates.

USER: Sure, I want to travel on June 13 and need to return on June 15.

ASSISTANT: Do you have any preference?

USER: I need a connecting flight.

ASSISTANT: Can I know your name?

USER: I am Frank Hall.

ASSISTANT: Sorry, there are no flights with your travelling dates.

USER: Ok, not an issue.

ASSISTANT: Thank you.

USER: Thank you for checking.