You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I am Joseph Mitchell here.

ASSISTANT: Ok.

USER: I want to visit my client's hometown, so please book my ticket from OAK to SEA.

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: My travelling dates are 02/19 and 02/21.

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

USER: No issues, thank you for your response.

ASSISTANT: You are welcome, have a great day.