You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I want to book a ticket from SEA to IAH. Could you book a ticket?

ASSISTANT: May I know your travelling dates?

USER: Depart is by May, 31 and return date is June, 2.

ASSISTANT: Do you prefer connecting flight?

USER: I would be comfortable with single stop over.

ASSISTANT: Do you have any other specifications?

USER: I prefer business class.

ASSISTANT: May I know your good name?

USER: I am Gregory Garcia.

ASSISTANT: Sorry, we found no flights on your travelling dates.

USER: Thanks.

ASSISTANT: Thank you for reaching us.