You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I address you today?

USER: Due to shortage of holidays I want o change my existing reservation. Can you please help me out?

ASSISTANT: Sure, I am here to help you.

USER: My name is Margaret Garcia.

ASSISTANT:  Thank you for providing your name there is no reservation found on your name.

USER: Ok, no problem.

ASSISTANT: Thank you for choosing us.

USER: Thanks for your response.