You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you at this moment?

USER: Samuel Garcia here. I want to change my existing reservation, can you please help me with that?

ASSISTANT: Sure. Can I have a moment please? Sorry, there is no reservation found on your name.

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

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