You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you at this moment?

USER: Andrew Martinez here. I want to book a flight ticket from LAX to OAK. Can you help me in that?

ASSISTANT: Sure, I am here to help you. Can you please provide your journey dates?

USER: My trip dates are Apr 16 to Apr 18.

ASSISTANT: Do you have any connection limit for this trip?

USER: I need a flight with single connection.

ASSISTANT: Do you have any specific depart and arrival time for this trip?

USER: My depart time should be in the evening.

ASSISTANT: Do you have any other specification for this trip?

USER: No.

ASSISTANT: Andrew Martinez, there are no flight services available on this route with your preferences.

USER: Ok, no problem. Thank you for checking.

ASSISTANT: Thank you for utilising our service.