You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Can you please help me to book a flight from PHX to LAS?

ASSISTANT: Sure, may I know the travelling dates?

USER: I want to depart on Jan 26 and need to return on Jan 28.

ASSISTANT: Do you have any connection limit?

USER: I am looking for a flight with single connection.

ASSISTANT: Is there any other requirements?

USER: I prefer an economy class to travel.

ASSISTANT: May I know your name?

USER: My name is Debra Davis.

ASSISTANT: Please wait a moment.

USER: Sure, I'll wait for your response.

ASSISTANT: Sorry, no flights found with your preferable dates.

USER: Oh! That's ok, thank you for giving the information anyways.

ASSISTANT: Thank you for opting us.