You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello. How can I guide you?

USER: Please book a ticket from Detroit, MI-DTW to Denver, CO-DEN.

ASSISTANT: I am here to help you. Can you please let me know your travelling dates?

USER: Ok. Departure is on 12/10 and 12/12 is my return.

ASSISTANT: Please tell me your name?

USER: My name is Kevin Brown.

ASSISTANT: Sorry, no flight found on your respected dates.

USER: Thanks for your guidance.