You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: Edward Young here. I would like to change my recent reservation, can you help me?

ASSISTANT: Ok, let me check with your existing reservation for a moment.

USER: Sure.

ASSISTANT: Thank you for waiting.

USER: It's ok.

ASSISTANT: I'm so sorry to inform you, there is no reservation found by your name in our data base.

USER: That's fine, anyway thanks for your help and valuable information.

ASSISTANT: Thank you for approaching our agency.