You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Due to some disturbances in my office, I would like to change my existing reservation. Please help me out.

ASSISTANT: Sure, I am here to help you with this.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: My name is Donna Brown.

ASSISTANT: Please wait for a mean while.

USER: Sure.

ASSISTANT: Sorry Donna, there is no reservation found under your name to change it.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: You are welcome.