You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello. How can I aid you?

USER: Please change my existing reservation, owing to an emergency.

ASSISTANT: Sure, I can help you. Can I know your name?

USER: My name is Alexander Miller.

ASSISTANT: Give me a minute.

USER: Ok.

ASSISTANT: Thanks for being waiting. We didnt found any reservation by this name.

USER: Thanks for the help.

ASSISTANT: Thank you for picking us.