You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I want to change my existing reservation to attend for a conference, due to some issues it has been postponed. Can you please help me to change it?

ASSISTANT: Sure, we are here to help you. May I know your name?

USER: Frank Hall is my name.

ASSISTANT: Ok, wait for some time I will check and get back to you.

USER: Sure.

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

USER: Ok, thanks for your help.

ASSISTANT: Thanks for approaching us.