You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

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

ASSISTANT: Sure, may I know your name?

USER: Sure, my name is Cynthia Carter.

ASSISTANT: Ok, please wait for a minute.

USER: Ok.

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

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

ASSISTANT: Thank you for contacting us.