You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I need you to book a flight ticket to reach Houston. So that I can attend my friends wedding. Please help me.

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

USER: January 27 and 29 are my planned travelling dates.

ASSISTANT: Can I know your source airport code please?

USER: AUS and HOU are my in and out airport codes.

ASSISTANT: Do you have any other requirements?

USER: I need to fly in a connecting flight.

ASSISTANT: Can I know your name please?

USER: My name is Benjamin Smith.

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

USER: Thant's ok. Thank you.

ASSISTANT: Most welcome.