You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER:  I just want to change an existing reservation as my meeting got post pone due to some technical issues. Can you help me?

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

USER: Thank you.

ASSISTANT: Ok, please wait a minute.

USER: Sure, Mark Lewis.

ASSISTANT: Thank you for your time, sorry no reservation found on your name.

USER: No issue.

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

USER: Thank you for the information.