You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: I want your help in making some changes in my existing reservation, due to the busy schedule on my previously planned dates. Can you please change my existing reservation?

ASSISTANT: Sure, May I know your name?

USER: Sure, I am Jason Scott.

ASSISTANT: Please wait a second.

USER: Ok.

ASSISTANT: Sorry, No reservation found on your name.

USER: Ok, Thank you for your help.

ASSISTANT: Thank you for opting us.