You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I would like to change my existing reservation, please help me out.

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: May I know your name to proceed?

USER: My name is Michelle Gonzalez.

ASSISTANT: Ok, please wait.

USER: Sure, take your time.

ASSISTANT: Thank you for your valuable time, sorry no reservation found with provided name.

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

ASSISTANT: Thank you for availing us.