You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How could I aid you?

USER: My name is Jason King. I am planning to attend my grandmother 60th anniversary.I need to book book a flight ticket from DC-IAD to TX-IAH.

ASSISTANT: Sure, At what dates would you like me to book a flight ticket?

USER: My travelling dates are from 10/14 to 10/16.

ASSISTANT: Ok, Please wait a minute. I will check and get back to you.

USER: Sure.

ASSISTANT: Thank you for waiting. There is no flight found based on your requirements.

USER: Ok, thanks for your information.

ASSISTANT: Thank you for reaching us, Have a nice day.