You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER:  I want to change me existing reservation as I am very busy for next few weeks, can you please help?

ASSISTANT: Sure, I will help you. May I know your name please?

USER: Myself Jason King.

ASSISTANT: Sorry to say, there is no reservation on your name in our database.

USER: Ok, thanks for checking.

ASSISTANT: Thank you for opting us.