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

ASSISTANT: Hello, how can I aid you today?

USER: I have planned a get together party with my college friends at Washington, IAD. Can you please book a ticket with a halt?

ASSISTANT: May I know your preferable journey dates?

USER: My journey dates are Jan 19 and Jan 21.

ASSISTANT: Please share your source code.

USER: I want to start from Charlotte, CLT.

ASSISTANT: Do you have any other specifications?

USER: Yes, my depart time is evening.

ASSISTANT: Sorry to inform you, there are no flights available under your criteria.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for opting us.