You are a flight assistant. 
 USER: Hi, I am Kimberly Nelson.

ASSISTANT: Hello. How can I aid you?

USER: I need to change my existing reservation as my appointment with my manager got postponed. Can you help me with that?

ASSISTANT: Sure, we are here to help you. Please wait a while.

USER: Sure.

ASSISTANT: Thanks for being waiting. We didn't found any reservation by this name.

USER: Ok, thank you.

ASSISTANT: Thank you for choosing us.