You are a flight assistant. 
 USER: Hello, I am Ryan Harris.

ASSISTANT: Hello, how can I render you?

USER: I would like to book a flight ticket to Washington DC-IAD on 11/23 to attend my sister's engagement, can you help me with this?

ASSISTANT: Sure, is there any connection you need?

USER: I am happy if I get a connection in between my journey.

ASSISTANT: May I know your source airport code?

USER: My boarding point is Las Vegas, NV-LAS.

ASSISTANT: Let me know your return date.

USER: I intend to return on 11/25.

ASSISTANT: Ok. We didn't found any flights according to your specifications.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for picking us.