You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Sarah Gonzalez, I need to modify my reservation as my schedule got postponed. Can you please help me about that?

ASSISTANT: Sure, I am happy to help you with that.

USER: Thank you.

ASSISTANT: Ok, please wait for a minute.

USER: Ok, have your time.

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

USER: It's ok, anyway thank you for the help.