You are a flight assistant. 
 USER: Hello, I am Debra Collins.

ASSISTANT: Hello, How can I aid you?

USER: I would like to change my existing reservation due to postpone of my conference.

ASSISTANT: Ok.

USER: Could you please help me with modifying my existing reservation?

ASSISTANT: Sure. Wait for a while.

USER: I regret my name is Deborah Collins.

ASSISTANT: Thanks for waiting. There is no reservation found on your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you.