You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I'm Shirley Thompson, want to change my reservation because I have some urgent work  on my previous reservation dates. Can you change my reservation?

ASSISTANT: Sure, please wait for a while, I will check and revert you back.

USER: Ok.

ASSISTANT: Sorry Shirley, there is no reservation found with your name in our records.

USER: It's ok, thank you for your information.

ASSISTANT: You are most welcome.