You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Susan Lewis. I want to change my recent reservation as my exam got postponed. Please help me out.

ASSISTANT: Sure, I will help you. Please wait for some time.

USER: Ok, take your time.

ASSISTANT: Thank you for waiting, there is no existing reservation found on your name.

USER: No problem, thank you for the response.

ASSISTANT: Thank you for choosing us, have a great day ahead.