You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I be of your helping hand?

USER: I want to change my existing reservation due to postpone of my exam, can you please help me with that?

ASSISTANT: Sure, may I know your name please?

USER: My name is Sharon Anderson.

ASSISTANT: Wait a while.

USER: Sure.

ASSISTANT: Thank you for your time, we did not find any active reservation in your name to make changes.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.