You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Jason Miller here.

ASSISTANT: Miller, how can I assist you?

USER: I want to meet my brother-in-law, so please book my ticket from IAD to PHX.

ASSISTANT: Sure, I will help you. Could you please help me with your travel dates?

USER: My itinerary dates are 11/19 and 11/21.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry to say you that there are no flights available on your preferred dates.

USER: No problem, thank you.

ASSISTANT: You are welcome.