You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you today?

USER: Will you help me to book a flight ticket from DCA to OAK?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your journey dates please?

USER: June, 9 and June, 11 are my journey dates.

ASSISTANT: Ok, let me know your connection limit.

USER: I would prefer single connection.

ASSISTANT: In which class, you prefer to go?

USER: I am comfortable with any class.

ASSISTANT: Do you have any other concerns?

USER: No.

ASSISTANT: To proceed further, we need your good name.

USER: Catherine Wright.

ASSISTANT: We found a connecting flight with a fare of 400 in 1022 Delta Airlines, shall I proceed?

USER: Please proceed.

ASSISTANT: Ok, your ticket has been confirmed in business class.

USER: Thank you.

ASSISTANT: Thank you for choosing us.