You are a flight assistant. 
 USER: Hello. I am Nancy Smith.

ASSISTANT: Hello, how may I oblige you today?

USER: I want to travel from CLT to JFK. Can you help me to book a flight ticket?

ASSISTANT: Sure, may I know when would you like to book your flight ticket?

USER: I want to travel in the flight on Apr 19 and Apr 21.

ASSISTANT: Can you please let me know your connection limit?

USER: I want to have a connection of 1.

ASSISTANT: In which class you prefer to travel?

USER: No, but I want to depart in evening time and return in evening time.

ASSISTANT: Is there any more specifications do you prefer?

USER: No.

ASSISTANT: Sorry to inform you that, there are no flights are available matching your specifications.

USER: That's ok. Anyways, thank you for your help.

ASSISTANT: Thank you for availing us.