You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you today?

USER: Can you please help me in booking my flight ticket from DEN to IAH?

ASSISTANT: Sure, help me with the travel dates?

USER: My travelling dates are Dec 20 and Dec 22.

ASSISTANT: Do you have any preferences?

USER: I need direct flight.

ASSISTANT: May I know your name please?

USER: Myself Christine Jones.

ASSISTANT: Sorry, no flights were available at this moment.

USER: Ok, thanks for your information.

ASSISTANT: Thank you for reaching us.