You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I am Susan Gonzalez. I need to book a flight ticket from DFW to LAS, Can you please help me for booking?

ASSISTANT: Yes, I can help you. Can you share me your travelling dates?

USER: I would like to travel on 12/20 to 12/22.

ASSISTANT: Give me a moment.

USER: Sure.

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

USER: Ok, no problem.

ASSISTANT: Thank you for contacting us.

USER: Thanks for your information.