You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am Cynthia Clark. Due to an emergency work. I could not attend the documentation.So I would like to change my existing reservation. Can you please help me?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry to say that, there was no reservation found with your name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for opting us.