You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Rachel Wilson here. I am planning to visit Denver, can you please book me a ticket from EWR to DEN?

ASSISTANT: Sure, I am here to help you out. Please provide me your trip dates.

USER: My preferable journey dates are from 02/18 to 02/20.

ASSISTANT: Sorry Wilson, there is no flight in your route.

USER: Ok, not an issue. Thank you for providing information.

ASSISTANT: Thank you for reaching us.