You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: Jack Rodriguez here. I would like to change an existing reservation where I have a meeting to attend.

ASSISTANT: Ok, I can help you with that. Please wait for a while.

USER: Sure, take your time.

ASSISTANT: Jack Rodriguez, there is no active reservation found under your name to do modifications in that.

USER: No issue, thank you for the information and your time.

ASSISTANT: Thank you for choosing us.