You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: My name is Emily Garcia. I want to prepone my trip. So, can you please change my existing reservation?

ASSISTANT: Sure, please wait I will let you know.

USER: Ok.

ASSISTANT: Sorry, no reservation found on your name. Thank you for contacting us, have a good day.

USER: That's fine, thank you for your quality service.