You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I want to book a flight ticket from SFO to CLT, can you please help me?

ASSISTANT: May I know your travelling dates?

USER: My planned dates are Apr 20 and Apr 22.

ASSISTANT: Can I know your class preference?

USER: I prefer economy class.

ASSISTANT: May I know your connection limit?

USER: I need a connecting flight.

ASSISTANT: Can I know your name?

USER: Gregory Lopez here.

ASSISTANT: Sorry, no flights found on your route.

USER: No problem , thank you for checking.

ASSISTANT: Most welcome.