You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I serve you at this moment?

USER: I am Paul Green. Can you help me in booking a flight ticket from EWR to ORD?

ASSISTANT: Sure, I will help you. Please send your travelling dates.

USER: I want to travel on 04/14, and return on 04/16.

ASSISTANT: Do you have any class or time preferences?

USER: I need to return in the evening time.

ASSISTANT: Sorry, there is no flight available on your journey dates.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: You are welcome, have a nice day.