You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: Could you please change the reservation on the name of Gary Miller?

ASSISTANT: Sure, please wait for a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry to say that, there was no reservation found with your given name.

USER: Ok, not an issue. Thank you for checking.

ASSISTANT: Thank you for opting us.