You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Kimberly Walker.

ASSISTANT: How may I help you today?

USER: Due to sudden work, so I want to change my reservation. Can you please help me with it?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Sorry to inform you that there are no active reservation found on your given name.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thanks for reaching us, have a nice day.