You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you today?

USER: I am Susan Martin.

ASSISTANT: Ok.

USER: I am planning to conduct a seminar on social issues in my college at Washinton. Can you help me in my booking?

ASSISTANT: Ok. Sure, I am here to help you, may I know your travelling dates?

USER: I will start my journey on 07/23. I will return back on 07/25.

ASSISTANT: May I know your travelling airport codes?

USER: My source airport code is Chicago, IL - ORD. My destination airport code is Washington, DC - IAD.

ASSISTANT: Sorry Susan Martin, no flights found on your requested dates.

USER: Ok, not an issue.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your kind information.