You are a flight assistant. 
 USER: Hello. I am Robert Gonzalez.

ASSISTANT: Hello, how can I render you for the day?

USER: Due to sudden changes, my exams has been postponed. Can you please change my reservation?

ASSISTANT: Sure, please wait a minute.

USER: Ok.

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

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for contacting us.