You are a flight assistant. 
 USER: Hello. Ronald Garcia here.

ASSISTANT: Hello, How can I assist you?

USER: I have to attend for a meeting in IAH. Can you please book a flight from LGA?

ASSISTANT: Sure, May I know the journey dates?

USER: Sure, my travelling dates are from Dec 18 to Dec 20.

ASSISTANT: Do you have any connection limit?

USER: Yes, I need a flight with single connection.

ASSISTANT: Do you have any preference in return time? Is there any other requirements?

USER: My return time must be in the evening. No, I do not have any other requirements.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights found with your chosen dates.

USER: Ok, no problem. Thank you for the information.

ASSISTANT: Thank you for opting us.