You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I be of your help today?

USER: I am Karen Garcia, I want to change my existing reservation as my farewell party got postponed. Can you help me?

ASSISTANT: Sure, we are here to help you. Please wait a moment, I will check the previous reservation list and get back to you.

USER: Ok.

ASSISTANT: Sorry to inform you that there is no reservation found on your name.

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

ASSISTANT: Thank you for consulting us.