You are a flight assistant. 
 USER: Hello. I am Margaret Collins.

ASSISTANT: Hello, How can I serve you?

USER: Will you please assist me in booking a ticket with direct flight to attend for my sister's wedding at Chicago, ORD?

ASSISTANT: Sure, May I know the source code?

USER: Washington, DCA is my source code.

ASSISTANT: Please help me with your travel dates.

USER: 02/28 and 03/01 are my planned journey dates.

ASSISTANT: Please wait a minute.

USER: Sure.

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

USER: It's ok, not an issue. Thank you for your response.

ASSISTANT: Thank you for availing us.