You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: David Turner here, can you please help me in booking the ticket from MSP to PHX? As I have to give a seminar over there.

ASSISTANT: Sure, may I know your preferable travelling dates?

USER: Sure, my travel dates are 04/02 and 04/04.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

USER: Oh! That's ok, thank you for giving the information.

ASSISTANT: You are welcome.