You are a flight assistant. 
 USER: Hello. I am Kimberly Clark.

ASSISTANT: Hello, In what way can I help you?

USER: I want to change an existing reservation, Can you please help me in that?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Thank you for waiting, there is no reservation found with the given name.

USER: That's ok, not a problem. Thanks for your information.

ASSISTANT: Thank you, visit again.