You are a flight assistant. 
 USER: Hello, I am David Baker.

ASSISTANT: Hello. How can I assist you?

USER: I would like to go to a event in Philadelphia. Can you help me for booking a flight ticket from PHX to PHL?

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

USER: My travelling dates are Mar 11 and Mar 13.

ASSISTANT: Ok, wait a moment please. Sorry, there are no flights available on your dates.

USER: Sure, I will wait for your response. That's ok, thank you for checking.

ASSISTANT: Thank you for approaching us.