You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: Can you please help me to book a ticket from SEA to IAH?

ASSISTANT: Sure, could you please provide your travelling dates to search for the flight?

USER: I want to start on July 30 and return on Aug 1.

ASSISTANT: May I know your name?

USER: Helen Allen here.

ASSISTANT: Do you have any specifications?

USER: I want to return in the evening. I would prefer a economy class.

ASSISTANT: May I know your connection limit?

USER: I need a connecting flight.

ASSISTANT: Sorry to say, no flight is available for you as per your requests.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for reaching us.