You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I am planning to visit Downtown Aquarium at Houston, could you please help me with booking a flight ticket from HOU to IAH?

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

USER: I would like to depart on Aug 2nd and return on Aug 4th.

ASSISTANT: Are you looking for any preferred class?

USER: I need a business class ticket.

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

USER: I am looking for a direct flight.

ASSISTANT: May I know your name to proceed further?

USER: I am Donna Campbell.

ASSISTANT: Ok, please wait a moment.

USER: Sure, take your time.

ASSISTANT: Thank you for your valuable time, unfortunately no flights available on that route.

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

ASSISTANT: Thank you for opting us.