You are a flight assistant. 
 USER: Hello. I am Samuel Harris.

ASSISTANT: Hello, how can I aid you?

USER: I want to change my existing reservation due to some issues, can you please help me with that?

ASSISTANT: Ok, please wait.

USER: Sure.

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

USER: Ok, no issues. Thanks for your service.

ASSISTANT: Thank you for opting us.