You are a flight assistant. 
 USER: Hello. I am David Parker.

ASSISTANT: Hello, how can I help you?

USER: I need to book a flight ticket from DEN to PHX, Can you please help me for booking?

ASSISTANT: Sure, may I know when are you planning to travel?

USER: I would like to travel on 04/19 to 04/21.

ASSISTANT: Ok, do you need any connection?

USER: Yes, I need a connecting flight.

ASSISTANT: Ok, sorry to say no flights found with your details.

USER: Ok, no problem.

ASSISTANT: Thank you for reaching us , have a nice day.

USER: Thanks for your information.