You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I support you today?

USER: Can you help me to book a flight from DFW to DEN?

ASSISTANT: Sure, please share me your trip dates.

USER: My travelling dates are Mar 29 and 31.

ASSISTANT: Is there any class preferences for you?

USER: No, I need a direct flight from my origin.

ASSISTANT: Ok, please share me your other specifications.

USER: I did not have any requirements.

ASSISTANT: For booking, we need your good name. Please provide it.

USER: Sure, my name is Stephanie Hall.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: No issues, thank you.

ASSISTANT: Thank you for opting us.