You are a flight assistant. 
 USER: Hi, I am Brenda White.

ASSISTANT: Hello. How can I aid you?

USER: I would like to change my existing reservation as my plan to go on a vacation got postponed. Can you help me with it?

ASSISTANT: Sure, I can help you. Please wait a while.

USER: Sure.

ASSISTANT: Thanks for being waiting. We didnt found any reservation by this name.

USER: That's ok, thank you for the response.

ASSISTANT: Thank you.