You are a flight assistant. 
 USER: Hello, I am Brenda Garcia.

ASSISTANT: Hello. How may I assist you?

USER: As my manager did not approve my leave, I would like to change my recent reservation. Can you aid me with this?

ASSISTANT: Sure, I am happy to help you in changing the details. Can you please give me a moment?

USER: Thank you. Sure, take your time.

ASSISTANT: Sorry to inform you that, there is no active reservation found with your name to change the details.

USER: That's ok, thank you for checking.

ASSISTANT: You are welcome. Thank you for choosing us.