You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Kenneth Hernandez here.

ASSISTANT: How can I help you?

USER: Can you please help me in changing my recent reservation? as my planned program has been postponed.

ASSISTANT: Just a moment please.

USER: Sure.

ASSISTANT: I am sorry, no reservation found on your name.

USER: That's ok, thank you for your service.

ASSISTANT: Thanks for choosing us.