You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: I am Rebecca Johnson. Can you please book me a ticket from OAK to PHL?

ASSISTANT: Sure, may I know your travel dates please?

USER: I would like to leave between 06/10 and 06/12.

ASSISTANT: Ok. Thanks for waiting. But I am sorry to say that there are no flights available.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you.