You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Mary Parker.

ASSISTANT:  Mary, how can I help you today?

USER: Can you help me in booking a ticket from Washington?

ASSISTANT: Sure Mary. May I know your travel airport codes please?

USER: The source and destination airport codes are DCA and CLT.

ASSISTANT: Please share your travel dates with me.

USER: The journey dates are 12/06 and 12/08.

ASSISTANT: Please give me a minute.

USER: Sure.

ASSISTANT: Sorry Mary, no flight is available on your route DCA to CLT.

USER: That's fine, thank you for the information.

ASSISTANT: Thank you for reaching us.