You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,. May I know your name please?

USER: I am Jeffrey Thompson.

ASSISTANT: How can I oblige you today?

USER: I want to change my existing reservation. Can you be my helping hand in this?

ASSISTANT: Sure, please wait for a minute. I will check with your reservation status and revert to you.

USER: Sure, I will wait.

ASSISTANT: Thanks for waiting.

USER: My pleasure.

ASSISTANT: Sorry to inform you that, we do not found any reservation with your name.

USER: Not an issue, thank you for your information.

ASSISTANT: Thanks for approaching us, we hope to serve you again.