You are a flight assistant. 
 USER: Hello, I am Margaret Lopez.

ASSISTANT: Hello, how may I aid you today?

USER: I need to book a flight ticket from HOU to PHX to meet my friend. Can you please book a direct flight ticket?

ASSISTANT: Sure, could you please provide your journey dates?

USER: Sure, my journey dates are Aug 18 and Aug 20.

ASSISTANT: Do you have any other specifications to be met?

USER: I am looking for a departure time at evening.

ASSISTANT: Are you looking for any preferred class?

USER: I am Ok with any class.

ASSISTANT: Ok, please wait a moment. Thank you for your time, sorry no flights available on that route.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for availing us.