You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I am John Phillips, want to travel from DFW to JFK. Can you book my ticket?

ASSISTANT: Sure, may I know your planned journey dates please?

USER: My journey dates are from 01/13 to 01/15.

ASSISTANT: Please wait a moment, John.

USER: Ok.

ASSISTANT: John, no flights has been found on your planned journey dates.

USER: That's fine, thank you.

ASSISTANT: Thank you for choosing us.