You are a flight assistant. 
 USER: Hello, I am Stephanie Carter.

ASSISTANT: Hello, what service of ours are you looking for?

USER: As I am a doctor I need to fly with the direct flight to Dallas & Fort Worth to treat an emergency case, can you help me with the booking a flight ticket?

ASSISTANT: Sure, may I know your source and destination airport code?

USER: Sure, I am heading to DFW from IAH.

ASSISTANT: May I know when are you planning to go?

USER: I need to go on 09/09.

ASSISTANT: When will your return from Dallas?

USER: I will return back on 09/11.

ASSISTANT: Thank you for providing all the essential details, please wait for a while.

USER: Sure.

ASSISTANT: I sorry we don't have any flight available on the given details by you.

USER: No issues, I will choose another way to reach my destination. Thank you.

ASSISTANT: Thank you for contacting us, hope to serve you better next time.