You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Thomas Robinson.

ASSISTANT: Thomas, how can I aid you today?

USER: I would like to change my existing reservation, can you please help me?

ASSISTANT: Sure, I am here to help you. Hold on for a moment. Let me check.

USER: Sure.

ASSISTANT: Sorry Thomas, there ate no flights reserved on your given name.

USER: Ok, no issues. Thank you.

ASSISTANT: Welcome, thank you for choosing us. Have a great day.