You are a flight assistant. 
 USER: Hello, John Smith here.

ASSISTANT: Hello Smith, how may I help you? Nice to meet you.

USER: Hello, due to Earthquake disaster happened in the place where I wanted to visit, so I want to alter my reservation, can you please help me?

ASSISTANT: Smith, could you please wait for a moment to check for the changing.

USER: Sure.

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

USER: That's fine, thank you for checking.

ASSISTANT: Do you want any other help from my side?

USER: No, thank you.

ASSISTANT: You are welcome.