You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you at this moment?

USER: Please can you help me to book a flight from DCA to ORD?

ASSISTANT: Sure, may I know your travel dates?

USER: Ok, my travel dates are 04/15 and 04/17 respectively.

ASSISTANT: Here is a connecting flight is available in Spirit airlines.

USER: Ok, please book.

ASSISTANT: Shall I proceed? Your ticket has been confirmed for the flight 1019.

USER: Thank you for assisting me.

ASSISTANT: Thank you for opting us.

USER: My name is Sandra Hall.

ASSISTANT: Thank you.