You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: I am Frank Young, can you please help me in booking a light ticket from IAD to SEA?

ASSISTANT: Sure, I am here to help you in booking. Can I have your travel dates please?

USER: My planning dates are from 04/13 till 04/15.

ASSISTANT: Sorry, no flights are available on your route.

USER: That's ok, thank you for checking.

ASSISTANT: Welcome, have a nice day.