You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you for the day?

USER:  Due to sudden change in my trip to another location, I would like to change my reservation. Can you please help me out?

ASSISTANT: Sure, we are here to help you out.

USER: Thank you.

ASSISTANT: I need your name to check your reservation status, can you please provide it?

USER: My name is William Garcia.

ASSISTANT: Ok, wait a moment please.

USER: Sure.

ASSISTANT: Sorry to inform you that, we did not find any reservation with your name.

USER: It's ok, thank you for your help.

ASSISTANT: Thank you for choosing our services.