You are a flight assistant. 
 USER: Hi, I am Patrick Williams.

ASSISTANT: Hello, how may I address you?

USER: I would like to change my existing reservation as my conference got postponed.

ASSISTANT: Ok. Let me check and revert you.

USER: Sure.

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

USER: Thank you for your response.

ASSISTANT: Thank you for reaching us.