You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Lisa Mitchell here.

ASSISTANT: Lisa, how can I assist you?

USER: Please book my ticket from SEA to PHX.

ASSISTANT: Sure, can you please let me know your travel dates?

USER: My trip dates are 09/20 and 09/22.

ASSISTANT: Ok, please wait for sometime.

USER: Sure.

ASSISTANT: Sorry Lisa, there is no flight available on your preferred dates.

USER: Thank you.

ASSISTANT: You are welcome and thank you for choosing us.