You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

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

ASSISTANT: Sure, let me know your travelling dates.

USER: I would like to depart on Sept 15th and return on Sept 17th.

ASSISTANT: Do you want connecting flight or direct flight?

USER: I am looking for a connecting flight.

ASSISTANT: Do you have any other requirements?

USER: Make sure that my return time must be evening.

ASSISTANT: May I know your name please?

USER: I am Carol Allen.

ASSISTANT: Ok, please wait for a while.

USER: Sure, take your time.

ASSISTANT: Sorry, there are no flights found with your given details.

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

ASSISTANT: Thank you for opting us.