You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Dorothy Perez. I have made a reservation earlier, due to some issues I need to change my existing reservation. Can you please help me with changing my reservation?

ASSISTANT: Sure, please wait for a moment to check your details.

USER: Sure.

ASSISTANT: Sorry to say, no reservation found on your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us, have a nice day.