You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I serve you at this moment?

USER: This is Mark Lopez. I would like to change my existing reservation, due to rainfall my food festival has been postponed. Can you please help me in changing?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry we did not find any reservation against your name in our database.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for choosing us.