You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Here Jessica Miller.

ASSISTANT: How can I aid you today?

USER: I am a travelling guide and I have to visit the Oakland-OAK to see the Scriptures and arts in the museums, so can you please help me in booking  a flight ticket from IAD to OAK ?

ASSISTANT: Sure, I am here to help you with that. Can I know your travelling dates?

USER: Thank you and my dates are on 12/10 and I will back after two days on 12/12.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry to say that, there are no flight's available based on your travelling dates.

USER: Sad to hear from your end, that's fine. Thank you for your help.

ASSISTANT: Thank you for reaching us.

USER: You are most welcome.