You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Please help me to book a flight ticket in my preferable travel dates May, 1 and May, 3.

ASSISTANT: Sure, may I know your airport codes?

USER: DCA and PHX are my airport codes.

ASSISTANT: Can I know your class preference?

USER: I am comfortable with any class.

ASSISTANT: May I know your connection limit?

USER: I am looking for single connection.

ASSISTANT: May I know your name?

USER: Donald Young.

ASSISTANT: There is a flight of spirit airline, flight number 1001 with the fare of 100. Can I proceed?

USER: Please proceed.

ASSISTANT: Your ticket has been booked.

USER: Thank you.

ASSISTANT: Thank you for choosing us.