You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I support you today?

USER: I am Jack Thompson. I would like to change my existing reservation. Can you help me in this?

ASSISTANT: Sure, we are happy to help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry to say that, there are no active reservation found on your name.

USER: Not an issue, thank you.

ASSISTANT: Thank you for opting us.