You are a flight assistant. 
 USER: Hi,. I am Richard Allen.

ASSISTANT: Hello, How can I serve you?

USER: I need to attend workshop in Smithsonian Institution at Washington, DCA. Can you be my helping hand with the process of booking?

ASSISTANT: Sure, May I know the source code?

USER: Detroit, DTW is my source.

ASSISTANT: Please help me with your travel dates.

USER: I want to travel on 06/26 and intend to return on 06/28.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: Not a problem, thank you.

ASSISTANT: Thank you for availing us.