You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I would like to change my reservation due to post pone of my sister's engagement. Please help me with it.

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

USER: Sure, I am Carolyn Clark.

ASSISTANT: Ok, please stand by I will get back to you.

USER: Ok.

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

USER: Fine, thanks for your information.

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