You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you?

USER: I am Jessica Baker. I wish to go for NASA space center at Houston, HOU. Can you please book a ticket for me?

ASSISTANT: Sure, may I know when have you planned to travel?

USER: Travelling dates are 10/25 to 10/27.

ASSISTANT: Kindly provide your source code.

USER: Source code is Washington, IAD.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Thanks for waiting. There is no flight with your respective dates of travel.

USER: No problem. Thank you.

ASSISTANT: Thanks for availing us.