You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: My collection function got postponed.I need to change my existing reservation, can you help me for change my reservation?

ASSISTANT: Sure, can I have your name please?

USER: My name is Paul Williams.

ASSISTANT: Ok, hold on I will get back to you.

USER: Sure.

ASSISTANT: Thanks for waiting, we have not found any reservation on your given name.

USER: Ok, Thanks for your information.

ASSISTANT: Ok, thanks for contacting us.