You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Please book a ticket from IAH to DTW to meet my sister on her birthday.

ASSISTANT: Sure, may I know your trip dates please?

USER: My travelling dates are Nov 1 and Nov 3.

ASSISTANT: Do you have any other requirements?

USER: I want single connection.

ASSISTANT: Can I know your name please?

USER: I am Dorothy Lee.

ASSISTANT: Sorry, we regret to inform you that there is no flight available as per your request.

USER: Ok, no worries. Thank you.

ASSISTANT: My pleasure.