You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I am Stephen King, I want to book a direct flight to meet my friend. Can you book a flight on 11/27 and return ticket on 11/29?

ASSISTANT: Sure, may I Know your source and destination codes?

USER: I will fly from DC-IAD to AZ-PHX.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry to say that, no flights were found with your given details.

USER: Thank you for the details.

ASSISTANT: Thank you for reaching us.