You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: I am Sharon Wilson. I would like to change my existing reservation, due to sudden change in my holiday trip. Will you help me ?

ASSISTANT: Sure, please wait for a moment.

USER: Sure.

ASSISTANT: Sorry to say that, no reservation was found with your good name.

USER: Ok. Thanks for sharing the information.

ASSISTANT: Thank you for reaching us.