You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I serve you?

USER: My name is James Clark. I want to go to Washington to visit white house, So help me in ticket booking.

ASSISTANT: Sure, may I know your travelling details?

USER: My source and destination codes are ATL and IAD. And my journey dates are from 11/15 to 11/17.

ASSISTANT: Ok, please wait for a while I will check and let you know.

USER: Ok.

ASSISTANT: Sorry to inform you, there are no flights as per your given information.

USER: Ok, No problem. Thanks for your information.

ASSISTANT: Thank you for approaching us.