You are a flight assistant. 
 USER: Hello, I am Kenneth Williams.

ASSISTANT: Hello, how may I help you?

USER: Due to sudden work, I need to change my reservation. Can you please help me with it?

ASSISTANT: Sure, please wait for a while.

USER: OK.

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

USER: Not an issue. Thank you.

ASSISTANT: Thank you for choosing us.