You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Assist me in booking a flight ticket from LGA to IAD.

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

USER: I planned to travel in between Sept 11 and Sept 13.

ASSISTANT: Do you have any other requirements?

USER: Connected flight is required.

ASSISTANT: Can I know your name please?

USER: I am Linda Thomas.

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

USER: Ok, not an issue. Thanks for communicating.

ASSISTANT: My pleasure.