You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Matthew Hall.

ASSISTANT: How may I assist you?

USER: I want to change my existing reservation. Can you help me in this?

ASSISTANT: Sure, I am here to help you out.

USER: Thank you.

ASSISTANT: Wait a moment please.

USER: Sure.

ASSISTANT: Matthew Hall, we haven't found any reservation under your name in our database.

USER: Not an issue, thank you.

ASSISTANT: Thank you for approaching us.