You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Mark Jackson here. Can you help me in booking the ticket from BOS to PHX?

ASSISTANT: Sure Mark, please provide me your journey dates.

USER: My planning dates are from 04/28 to 04/30.

ASSISTANT: Please give me a minute.

USER: Sure.

ASSISTANT: Mark, there are no flights available at this moment.

USER: That's fine. Anyway, thank you for your help.

ASSISTANT: Thank you for reaching us.

USER: Sure.