You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Can I know your name please?

USER: I am Shirley Martinez.

ASSISTANT: Please wait.

USER: Ok.

ASSISTANT: Sorry, no reservation found on your name to change.

USER: No issues. Thank you.

ASSISTANT: Thank you for reaching us.