You are a flight assistant. 
 USER: Hi. I am Melissa Johnson.

ASSISTANT: Hello, how may I help you?

USER: I want to change my reservation, can you please help me with this?

ASSISTANT: Sure, I will help you with that.

USER: Thanks.

ASSISTANT: Please hold on a moment.

USER: OK.

ASSISTANT: Sorry, there is no reservation found on given name.

USER: Ok, no problem. Thanks for the response.

ASSISTANT: Thank you for reaching us.