You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I am Elizabeth Collins. I want to change my reservation as my trip got postponed, can you please help me?

ASSISTANT: Sure, I will help you. Please hold on a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on given name.

USER: No problem, thank you for checking.

ASSISTANT: Thank you for reaching us.