You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you today?

USER: I would like to change my existing reservation, please help me out.

ASSISTANT: Sure, please be on hold. Can you please provide me your good name?

USER: Sure, my name is Nicole Baker.

ASSISTANT: Please be on hold.

USER: Sure.

ASSISTANT: I found your reservation, can you please share your airport codes?

USER: My airport codes are AUS and DEN.

ASSISTANT: May I know your journey dates please?

USER: My trip dates are 10/06 and 10/08.

ASSISTANT: UA airlines is having a flight on that route with travel charge of 200, shall I proceed booking?

USER: Ok, please book my ticket.

ASSISTANT: Your ticket has been changed successfully with flight-1024, have a safe journey.

USER: Thank you for your help.

ASSISTANT: Thank you for choosing us.