You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Can you please help me in changing my existing reservation, as my exam got postponed to some other date.

ASSISTANT: Sure, can I know your name please?

USER: Sure, my name is Matthew Carter.

ASSISTANT: Ok, please wait.

USER: Ok.

ASSISTANT: Thanks for waiting, there is no reservation found on your name in our data base.

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

ASSISTANT: Thank you for reaching us.