You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: Can you please change my existing reservation?

ASSISTANT: Sure, please share your good name?

USER: I am Brenda Williams.

ASSISTANT: Sure, please wait a moment.

USER: Ok, I will wait for your reply.

ASSISTANT: There is no reservation found on your given name.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for opting us.