You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is John Robinson.

ASSISTANT: How can I assist you today?

USER: I want to do some changes in my existing reservation. Can you help me for that?

ASSISTANT: Sure, please give me a minute.

USER: Sure, take your time.

ASSISTANT: Please give me your airport codes.

USER: My travelling airport codes are from LAS and EWR.

ASSISTANT: Can I know your travelling dates?

USER: My travelling dates are from 05/03 till 05/05.

ASSISTANT: Please give me a minute.

USER: Ok.

ASSISTANT: Here is a flight with ticket fare 100 in Spirit airlines. Is it ok for you?

USER: Ok, please proceed for booking.

ASSISTANT: Your booking is confirmed with flight number 1020. Thank you for contacting us, have a nice day.

USER: Thank you for booking.