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 LAS to PHX?

ASSISTANT: May I know your travel dates?

USER: My travel dates are 20 to 22 of May.

ASSISTANT: Do you prefer connecting flight?

USER: I need a connecting flight.

ASSISTANT: Do you have any other specifications?

USER: No.

ASSISTANT: May I know your good name?

USER: I am Lisa Lee.

ASSISTANT: Sorry, we found no flights on your travel dates.

USER: It's ok, not a problem, thank you.

ASSISTANT: Thank you for reaching us.