You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, How can I assist you?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Sure, May I know your name?

USER: My name is Pamela Perez.

ASSISTANT: Ok, please wait.

USER: Ok.

ASSISTANT: Thanks for waiting, we found reservation on your name. Please provide me your travelling dates.

USER: Ok, my planned trip dates are Oct 09-11.

ASSISTANT: Can I know your airport codes?

USER: My airport codes are DEN to SFO.

ASSISTANT: Do you have any preferences?

USER: I need a connecting flight.

ASSISTANT: You have a connecting flight 1020 in Frontier airline and price 200, Shall I proceed?

USER: Ok, please go ahead.

ASSISTANT: Your ticket has been reserved.

USER: Thank you.

ASSISTANT: Thank you.