You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: I am Ronald Lopez, can you help me to book a flight from LGA to JFK?

ASSISTANT: May I know your desired travel dates please?

USER: My travelling dates are Jan 23 and 25.

ASSISTANT: Do you have any other specifications?

USER: I want to return at evening.

ASSISTANT: Sorry to say, there is no flight on your desired travel dates.

USER: No issues, thank you for your time.

ASSISTANT: Thank you for opting us.