You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Dennis Smith.

ASSISTANT: How may I assist you at this moment?

USER: I planned to attend for a wedding in SFO, can you please help me to book a flight ticket from DTW?

ASSISTANT: Sure, I am glad to help you with that. Can you please provide your departure and return dates of travelling?

USER: I prefer to travel on 11/02 and 11/04.

ASSISTANT: Please wait a moment to check the flights availability in your route.

USER: Sure.

ASSISTANT: We regret to inform you that there are no flights moving to your region with your planned dates of travelling.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for reaching us, hope you have a great day.