You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I serve you today?

USER: I need to change my reservation as my plan to go for a Historical tour got postponed. Can you help me?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Can I know your name please?

USER: I am Brandon Perez.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name to change.

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

ASSISTANT: Thank you for contacting us.