You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you?

USER: Stephen King here, due to sudden work. I want to change my reservation. Can you please help me with it?

ASSISTANT: Sure, I will help you. May I know your name?

USER: I already mentioned above.

ASSISTANT: Sorry, there is no reservation existing on your name.

USER: Ok, not an issue. Thank you.

ASSISTANT: You are welcome,.