You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: I want to change my existing reservation due to some problems, can you please help me?

ASSISTANT: Sure, please provide me your name to check the status of your reservation.

USER: Sure, my name is Kimberly Walker.

ASSISTANT: Walker, please wait for a minute.

USER: Sure, take your time.

ASSISTANT: There are no active reservations found with your details, Walker.

USER: Ok, no problem. Anyways, thank you for your service.

ASSISTANT: Thank you for choosing us, have a good day.