You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, How can I provide service to you?

USER: I would like to change my existing reservation in the name of Jack Lopez. Can you help me in this?

ASSISTANT: Sure, we are here to assist you.

USER: Thank you.

ASSISTANT: Please be on hold.

USER: Ok.

ASSISTANT: Sorry, no active reservation found with your specified name.

USER: Not an issue, thank you.

ASSISTANT: Thanks for approaching us.