You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: I am Melisa Carter. I want to attend a party at New York, EWR. Can you please book a ticket on 09/15?

ASSISTANT: Sure, May I know the source code?

USER: Source code is Washington, IAD.

ASSISTANT: Please help me with your return date.

USER: Return is on 09/17.

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

USER: No problem. Thank you.

ASSISTANT: Thank you for opting us.