You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am Brenda carter. I want to change my existing reservation as my dates are changed. Can you help me out?

ASSISTANT: Ok, please wait a moment.

USER: Sure.

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

USER: Ok, no issues.

ASSISTANT: Thanks for reaching us.

USER: Thank you.