You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you?

USER: I am Gregory Thomas. I need a direct flight to reach Oakland as it is an urgent case, can you please help me with that?

ASSISTANT: Sure, may I know your depart and return date?

USER: Yes, I will depart on 05/13 and return back on 05/15.

ASSISTANT: Kindly provide your journey codes.

USER: I want to fly from ORD to OAK.

ASSISTANT: Please give me a minute.

USER: Ok.

ASSISTANT: There is no flight available with your requirements.

USER: No issues, thank you.

ASSISTANT: Thanks for availing us.