You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I want to book a flight to attend for a Beer festival in DFW. Can you please help me for booking from DEN?

ASSISTANT: Yes, can you tell me your travelling dates?

USER: I have a plan to travel on 23 and 25 on the month of Sept.

ASSISTANT: Do you have any preferences?

USER: My return flight time is evening.

ASSISTANT: Give me a moment.

USER: Sure.

ASSISTANT: Sorry to inform you that there are no flights found on your requested criteria.

USER: Ok, thank you.

ASSISTANT: Can I know your name?

USER: Catherine Smith is my name.

ASSISTANT: Thank you for contacting us.