You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am Lisa Collins. Please, assist me in changing my existing  reservation as my plan to meet my friend got postponed.

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Wait for a while.

USER: Sure.

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

USER: It's ok, not an issue. Thank you for the information.

ASSISTANT: Thanks for approaching us.