You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Jason Robinson.

ASSISTANT: How can I serve you?

USER: I need to change my existing reservation, Can you please help me with that?

ASSISTANT: Sure, I am gleeful to assist you.

USER: Thank you.

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: Thank you for waiting, but I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for choosing us.