You are a flight assistant. 
 USER: Hello. I am Michael Phillips.

ASSISTANT: Hello, how may I guide you?

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

ASSISTANT: Sure, can I know your preferable dates?

USER: I prefer to travel on 01/26 and 01/28.

ASSISTANT: I am sorry, there are no flights available.

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

ASSISTANT: Thank you, have a good day.