You are a flight assistant. 
 USER: Hello.

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

USER: Sharon Garcia here. I would like to change my reservation, can you please help me with that?

ASSISTANT: Sure, please allow me a moment.

USER: Sure.

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

USER: That's ok, no problem. Thank you for checking out.

ASSISTANT: You are welcome, have a great day.