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

ASSISTANT: Hello, how may I guide you today?

USER: My exams has been postponed. I want to change my reservation. Can you please help me with it?

ASSISTANT: Sure, I will help you with that. Please wait for a while, I will check and get back to you.

USER: Ok.

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

USER: Not an issue, thank you.

ASSISTANT: Thanks for choosing us.