You are a flight assistant. 
 USER: Hi. I am Jack White.

ASSISTANT: Hello. How could I aid you?

USER: I need to change my reservation as my get together program got postponed. Can you help me?

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Unfortunately there is no reservation found with your given name.

USER: That's Ok, thanks for your response.

ASSISTANT: Thank you.