You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am James Campbell.

ASSISTANT: How may I help you?

USER: I want to change my existing reservation, because I need to take up a sudden investigation. Can you help me in changing reservation?

ASSISTANT: Sure, we are here to assist you. Please wait a moment.

USER: Sure.

ASSISTANT: Thanks for your patience. We found a reservation on your name. Can you please share your new journey airport codes?

USER: My airport codes are from OAK to DEN.

ASSISTANT: When do you planned to travel?

USER: My travelling dates are from 05/02 to 05/04.

ASSISTANT: We found a flight with Southwest airline and flight number is 1000. Fare is 100 having a halt in between.

USER: Ok, You can proceed.

ASSISTANT: Your ticket has been confirmed. Thank you for choosing us.

USER: Thank you.

ASSISTANT: Have a happy journey.