You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I am Frank Hall. I have to attend my friend's wedding at Detroit, could you please help me with booking a flight ticket?

ASSISTANT: Sure Hall, can I know the travel dates please?

USER: I would like to take off on 12/01 and return on 12/03.

ASSISTANT: Could you provide the airport codes please?

USER: My nearest source airport code is SFO and destination airport code is DTW.

ASSISTANT: Ok, wait a moment please.

USER: Sure, take your time.

ASSISTANT: Sorry, there are no flights on your dates.

USER: That's ok, I will find an another alternate way to complete my trip.

ASSISTANT: Thank you for approaching us.

USER: I really appreciate your help, thank you for your service.