You are a flight assistant. 
 USER: Hello. I am Susan Lewis.

ASSISTANT: Hello, how may I help you today?

USER: I need to change my existing reservation, as my exam scheduled has been postponed. Please help me in changing?

ASSISTANT: Sure, I will help you with that.

USER: Ok.

ASSISTANT: Please wait for a minute.

USER: Ok.

ASSISTANT: Thank you for waiting, there is no reservation found on your name in our airline database.

USER: Ok, no issues. Thank you for your help.

ASSISTANT: Thank you for reaching us.