You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?

USER: Myself Charles Gonzalez. i would like to visit Washington, please help me in booking a ticket from HOU to IAD.

ASSISTANT: Sure, I will help you with that booking, may I know your travelling dates.

USER: My planned journey dates are 04/20 and 04/22.

ASSISTANT: Please wait a minute.

USER: Sure, take your time.

ASSISTANT: Sorry, there is no flight available on your desired route.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for opting us.