You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I want to change my existing reservation, my trip with my friends has been postponed. Can you please help me?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: May I know your name?

USER: My name is Catherine Lewis.

ASSISTANT: Ok, wait for some time.

USER: Sure.

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

USER: Ok, thanks for your service.

ASSISTANT: Thanks for approaching us.