You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I would like to visit Detroit to meet my grand parents, please help me in booking a ticket from PHX to DTW.

ASSISTANT: Sure, may I know your travel dates?

USER: My planned travel dates are on Apr 19 and Apr 21.

ASSISTANT: Do you have any class preference?

USER: Any class is comfortable for me.

ASSISTANT: Is there any connection limit?

USER: I need a connecting flight.

ASSISTANT: Any other specifications to be met?

USER: I would like to depart in the afternoon.

ASSISTANT: May I know your name?

USER: My name is Gary Lee.

ASSISTANT: Ok, please wait a minute.

USER: Sure, take your time.

ASSISTANT: Sorry, there were no flights found on your route.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for contacting us.