You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation, can you please help me with this?

ASSISTANT: Sure, please share your good name?

USER: Sure, I am Andrew Martinez.

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Sorry, no reservation found on your given name.

USER: It's ok, thank you.

ASSISTANT: Thank you for choosing us.