You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you help me to change my existing reservation?

ASSISTANT: Sure, can I know your name please?

USER: My name is Ronald Garcia.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry Ronald, there is no active reservation found with your name in our records.

USER: No issues, thank you for the checking.

ASSISTANT: Most welcome.