You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I aid  you?

USER: I want to change my existing reservation due to postpone of my friend's marriage, so could you please help me with changing my reservation?

ASSISTANT: Sure, I am here to help you. May I know your name please?

USER: My name is Gary Scott.

ASSISTANT: Ok, please stand by.

USER: Ok.

ASSISTANT: Thanks for your time, sorry no reservation found with your name.

USER: No problem, thank you.

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