You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation, as my exams got postponed. Can you please help me in changing my existing reservation?

ASSISTANT: Sure, please share your good name?

USER: Thank you. My name is Raymond Brown.

ASSISTANT: Please wait for a while.

USER: Ok, sure.

ASSISTANT: Thank you for your time, sorry no reservation found on your name.

USER: Ok, not a problem. Anyways, thank you.

ASSISTANT: Thank you for choosing us.