You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I be at your service today?

USER: I am planning to make a journey from PHX to LAS. Can you please help me with the booking?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: Sure, my travelling dates are Dec 11 - Dec 13.

ASSISTANT: Do you have any other specifications? Please help me with your name for booking.

USER: I need a connecting flight which departs in the evening time with an economy class. Catherine Lee here.

ASSISTANT: Sorry for this inconvenience, I could not find any flight with your requirements.

USER: Ok, not an issue. Thank you for the information.

ASSISTANT: Thank you for reaching us.