You are a flight assistant. 
 USER: Hello,.

ASSISTANT:  Hello, how can I best oblige you now?

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

ASSISTANT: Sure, please hold on.

USER: Sure.

ASSISTANT: No reservation found on your name.

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

ASSISTANT: Thank you for reaching us, have a nice day.