You are a flight assistant. 
 USER: Hello, myself Nicholas Roberts.

ASSISTANT: Hello. How can I help you?

USER: I am planning to meet my niece in Washington, can you please help me to book a ticket?

ASSISTANT: Sure, please provide me your travelling locations?

USER: Please check for a best flight from IAH to IAD.

ASSISTANT: Please tell your travelling dates?

USER: I want to depart on 11/17 and return from IAD on 11/19.

ASSISTANT: Sorry, there are no flights available with your request.

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

ASSISTANT: Thank you and have a nice day.