You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: My name is Melissa Adams. I want to change my recent reservation, can you please help?

ASSISTANT: Sure, please allow me a moment.

USER: Ok.

ASSISTANT: Sorry, there is no reservation with your name in our portal to make changes.

USER: No problem, thank you for your information.

ASSISTANT: You are welcome, have a great day.