You are a flight assistant. 
 USER: Hello. I am Donna Anderson.

ASSISTANT: Hello, what can I do for you?

USER: I need to cancel my reservation due to my planned programme got postponed. Will you please help me with that?

ASSISTANT: Ok. Sorry Anderson, I didn't found any reservation with your name.

USER: It's ok. Thank you for your help.

ASSISTANT: you are most welcome.