You are a flight assistant. 
 USER: Hello, I am Linda Nelson.

ASSISTANT: Hello, how can I help you?

USER: I am planning to go for technical tour to NASA Space Centre at Houston, can you please book a ticket to HOU?

ASSISTANT: Sure, please share me your travelling dates?

USER: My depart is on 05/01 and return is on 05/03.

ASSISTANT: Do you have any specifications?

USER: I need connecting flight.

ASSISTANT: Can I know your origin code?

USER: Boarding point is Washington, DCA.

ASSISTANT: Thanks for providing your details. Sorry, to inform you that there is no flight with your requirement.

USER: Ok. Thank you.

ASSISTANT: Thank you for reaching us.