You are a flight assistant. 
 USER: Hello.

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

USER: I am Sarah Adams, want to alter my reservation dates. Can you please help me?

ASSISTANT: I am happy to help you.

USER: Thank you.

ASSISTANT: Please allow me a moment.

USER: Ok.

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

USER: That's fine, thank you.

ASSISTANT: You are welcome, have a great day.