You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: Please help me to book a direct flight from Chicago to treat an emergency case in Oakland.

ASSISTANT: Can you share your trip source and destination?

USER: I would like to start my journey from ORD and my destination airport code is OAK.

ASSISTANT: What are your travel dates?

USER: Sure, I need to depart on 11/17 and my return date will be on 11/19.

ASSISTANT: Are there any other preferences?

USER: No more specifications please.

ASSISTANT: May I know your name?

USER: I am Stephanie Parker.

ASSISTANT: Sorry, there is no flight found under your details.

USER: That's ok, not an issue. Thank you.

ASSISTANT: Thank you for reaching us.