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

ASSISTANT: Hello, how can I help you?

USER: My sisters engagement has been preponed. I want to change my existing reservation. Could you please help me with it?

ASSISTANT: Sure, please wait for a minute, let me check and revert you.

USER: Ok.

ASSISTANT: Thanks for waiting, there is no reservation with your name.

USER: Not a problem, thank you.

ASSISTANT: Thank you, for opting us.