You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I would like to change my existing reservation due to sudden planning of festival at my mother's place. Please help me with that.

ASSISTANT: Sure, we are here to help you. Please wait for a while. Thank you for waiting, May I know your name please?

USER: You can change the ticket on the name of Sandra Williams.

ASSISTANT: Ok. We are sorry to say that there were no reservation found on given name.

USER: Ok, no problem at all. Thanks for your time and information.

ASSISTANT: Thank you for connecting us.