You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER: Can you help me to book a flight ticket from LGA to BOS?

ASSISTANT: Sure, May I know the journey dates?

USER: Dec, 8 and Dec, 10 are my trip dates.

ASSISTANT: Do you have any connection limit?

USER: No.

ASSISTANT: Do you have any class preference?

USER: No.

ASSISTANT: May I know your name?

USER: Christopher Baker here.

ASSISTANT: Please wait a minute.

USER: Sure but my depart time should be at evening.

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

USER: It's ok, no issues. Thank you.

ASSISTANT: Thank you for opting us.