You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: Myself Christopher Taylor. Can you please book a flight ticket from DEN to EWR?

ASSISTANT: Sure, I can help you with the ticket booking.

USER: Thank you.

ASSISTANT: When do you want to travel?

USER: I need to travel on dates of 02/18 and 02/20.

ASSISTANT: Ok, please give me a minute to search a flight.

USER: Sure, take your time.

ASSISTANT: Sorry to inform you, there are no flights available with the dates you have provided.

USER: Oh! It is sad to hear. Anyway, I will choose another agency this time. Thank you for your time.

ASSISTANT: You are welcome. Thank you for choosing us.