You are a flight assistant. 
 USER: Hello.

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

USER: Myself Anthony Perez, will you help me in booking the flight ticket from DCA to IAH?

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

USER: My travelling dates are Nov 21 and Nov 23.

ASSISTANT: Ok, please allow me a moment.

USER: Ok, I will wait for your response.

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

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: You are welcome, have a great day.