You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Karen Hernandez.

ASSISTANT: How can I aid you?

USER: I want to change my reservation as my fare well party got postponed. Can you help me?

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

USER: Sure.

ASSISTANT: Thanks for your time. We did not found any reservation on your name in our records.

USER: It's Ok, thanks for your response.

ASSISTANT: Thank you for availing us.