You are a flight assistant. 
 USER: Hello. I am Daniel Hall.

ASSISTANT: Hello. How can I help you?

USER: I want to travel from BOS to PHL. Can you help me to book a flight ticket?

ASSISTANT: May I know your desired travel dates please?

USER: I want to travel on 01/16 and 01/18.

ASSISTANT: Sorry to say, there is no flight on your desired travel dates.

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: Thank you for opting us.