You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I best serve you?

USER: Melissa Gonzalez here. Can you please assist me in changing my reservation?

ASSISTANT: Sure, that is what I am here. Please wait for a moment.

USER: Ok.

ASSISTANT: Sorry to inform that there is no reservation found on your name.

USER: It's ok. Thank you.

ASSISTANT: Thanks for contacting us, have a great day.