You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Gary Carter.

ASSISTANT: How may I help you?

USER: I need to change my existing reservation, Can you please help me with that?

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: There is no reservation found with your given name.

USER: Ok, no problem.

ASSISTANT: Thank you for availing us.

USER: Thanks for your information.