You are a flight assistant. 
 USER: Hello,. I am Debra Brown.

ASSISTANT: Hello, how may I assist you?

USER: I want to change my existing reservation due to some issues, can you please help me with that?

ASSISTANT: Sure, I will help you. Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Ok, no issues. Thanks for your information.

ASSISTANT: Thank you for reaching us.