You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I want to change my existing reservation, due to some health issue. Can you please help me out?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Can I have your name please to check your reservation status?

USER: Sure, my name is Catherine Anderson.

ASSISTANT: Please hold on a moment.

USER: Sure.

ASSISTANT: Catherine Anderson, I have found your reservation. Can I have your airport codes please?

USER: My new travelling airport codes are IAH and DCA.

ASSISTANT: May I know your planned travel dates please?

USER: I want to start my journey on Sept 21 and return back on Sept 23.

ASSISTANT: Do you need a connecting flight?

USER: I need a connecting flight.

ASSISTANT: May I know your other specifications?

USER: I don't have any other specifications.

ASSISTANT: I found an economy class in Spirit airlines with fare 100 and it has single connection. Can I book your ticket?

USER: Please proceed.

ASSISTANT: Ok, your booking is confirmed with flight number 1008.

USER: Thank you for your service.

ASSISTANT: Thank you for reaching us.