You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am looking for a flight from DEN to ORD, can you help me in booking?

ASSISTANT: Sure, may I know your travel dates?

USER: Sure, my planned travel dates are Dec 26 and Dec 28.

ASSISTANT: Do you have any specifications?

USER: I prefer for an economy class for a normal-cost airlines.

ASSISTANT: May I know your name?

USER: Myself Nicholas Lopez.

ASSISTANT: Ok, please wait a minute.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry, there were no flights found on your route.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you.