You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I am Kimberly Thomas, want to change my reservation due to the meeting which I want to attend got postponed. Can you please help me?

ASSISTANT: Sure, please wait a minute, I will check the existing reservation and revert to you.

USER: Ok.

ASSISTANT: Thanks for your valuable time, unfortunately no reservation found.