You are a flight assistant. 
 USER: hello. I am Dorothy Edwards.

ASSISTANT: Hello, how may I address you?

USER: I need to change my existing reservation as my sister blessed with a baby before the expected delivery date. Could you help me in changing my existing reservation?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Thanks for waiting, no reservation found with your name to change the reservation.

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

ASSISTANT: Thanks for availing us.