You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: Can you please help me in changing my existing reservation, as my exams got postponed?

ASSISTANT: Sure, I am here to help you out. Can you please mention your name to check your reservation status?

USER: Thank you, my name is William Campbell.

ASSISTANT: Ok, please give me a moment.

USER: Ok, sure.

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

USER: Ok, not an issue. Anyways, thank you for the information.

ASSISTANT: Thank you for reaching us.