You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Emily Campbell.

ASSISTANT: How can I aid you?

USER: I would like to visit The Heritage Society in Houston to study about 19th century houses. So please help me in booking a flight ticket with single connection.

ASSISTANT: Sure, I can help you. Can I know your travelling dates?

USER: Sure, My planned dates are 07/25 and 07/27.

ASSISTANT: Please share me your airport codes.

USER: I will take off from IAD and land at IAH.

ASSISTANT: Give me a minute.

USER: Ok.

ASSISTANT: Thanks for your time. Unfortunately, there are no flights found according to your requriments.

USER: No problem, thank you for your information.

ASSISTANT: Thank you for choosing us.