You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: Could you please change my existing reservation due to postpone of my exams?

ASSISTANT: Sure, could you please provide your name?

USER: My name is Debra Hernandez.

ASSISTANT: Please wait for a moment to check.

USER: Sure.

ASSISTANT: Sorry to say, no reservation found on your name.

USER: Not a problem, thank you for checking.

ASSISTANT: Thank you for reaching us.