You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello.

USER: I am Amy Allen.

ASSISTANT: How can I help you at this moment?

USER: Can you help me in booking a flight ticket from SFO to LAS?

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

USER: I want to travel on 12/29, and need to catch return flight on 12/31.

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

USER: I need a connecting flight.

ASSISTANT: Do you have any class preference for this trip?

USER: I am comfortable with any class.

ASSISTANT: Do you have any airline preference for this trip?

USER: No, but I want to depart in the morning time.

ASSISTANT: Amy Allen, we regret to inform you that there are no flight services available with your preferences on this route.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Thank you for contacting us.