You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I need to change my existing reservation, can you help me in doing that?

ASSISTANT: Sure, may I know your name please?

USER: I am Raymond Allen.

ASSISTANT: Ok, please wait for a moment.

USER: Sure.

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

USER: Ok, no issues. Thank you for the information.

ASSISTANT: Thank you for opting us.