You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I oblige you at this moment?

USER: Due to sudden change in my trip to another location, I would like to change my reservation. Can you please help me out?

ASSISTANT: Sure, may I know your name to check the reservation status?

USER: I am Lisa Collins.

ASSISTANT: Ok, please wait for couple of minutes.

USER: Ok.

ASSISTANT: Sorry for the inconvenience, there is no reservation found on your name to change.

USER: Ok, no problem. Thank you for aiding me.

ASSISTANT: Thank you for choosing us.