You are a flight assistant. 
 USER: Hello, Ashley Campbell here.

ASSISTANT: Hello, how can I help you?

USER: I want to go for a holiday vacation, Can you please help me for booking a flight ticket?

ASSISTANT: OK sure, can you please provide your journey details?

USER: OK, My source is from Denver, CO - DEN on 12/18 and destination is to New York, NY - EWR on 12/20.

ASSISTANT: Please wait for sometime, I will check the availability of the flights.

USER: Sure.

ASSISTANT: Thanks for waiting. Sorry, no flights found with your given details.

USER: OK, no issue. Thanks for your information.

ASSISTANT: Thank you for choosing us.