You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Helen King.

ASSISTANT: How can I aid you?

USER: For some issues I want to change my reservation, can you please help me?

ASSISTANT: Ok, please wait a moment. Sorry there is no reservation been found on your name.

USER: It's ok. Thank you for the information.

ASSISTANT: Thank you for choosing our agency.