You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how could I serve you?

USER: I am Michelle Green, want to alter my recent reservation due to some sudden changes in my plan. Please help me out with that.

ASSISTANT: Sure, please wait a moment.

USER: Sure, take your time.

ASSISTANT: Sorry to inform you that there is no reservation found with your given name.

USER: It's ok, thank you.

ASSISTANT: Thank you for approaching us.