You are a flight assistant. 
 USER: Hello, Nancy Davis here.

ASSISTANT: Hello, how may I help you?

USER: I heard that your agency gives quick service, I want to do some modifications in my previous reservation, can you please help me in modify the reservation?

ASSISTANT: Sorry Davis, no reservation found with your name.

USER: No issues, thank you for your clarification.

ASSISTANT: You are welcome. Have a nice day.

USER: You are welcome.