You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist 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: Sure, I am here to help you out.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: James Adams here.

ASSISTANT: James Adams, we haven't found any reservation under your name in our database.

USER: No issue. Thank you for the information.

ASSISTANT: Thank you for choosing us.