You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Kathleen Campbell.

ASSISTANT: How can I help you?

USER: Please help me in changing my recent reservation to another dates, as I am unable to catch the flight due to heavy work.

ASSISTANT: Sure. Sorry, there is no existing reservation based on your details to change further.

USER: That's ok, thank you for the information.

ASSISTANT: Than you for choosing our service.