You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you today?

USER: I want to book a connecting flight ticket to meet my friends who will stay in CO. Can you help me?

ASSISTANT: Sure, I am here to assist you. Can you please provide your planned dates of journey?

USER: Thank you. 05/21 and 05/23 are my trip dates.

ASSISTANT: May I know your airport codes of journey please?

USER: DTW and DEN are my nearest airport codes.

ASSISTANT: Do you have any other specifications for this trip?

USER: I would like to depart in the evening.

ASSISTANT: May I know your good name please?

USER: Sure, Samantha Williams here.

ASSISTANT: Samantha Williams, we regret to inform you that there are no flight services are available on this route with your preferences.

USER: No issue. Thank you for the information.

ASSISTANT: Thank you for contacting us.