You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: Have a concern regarding the flight ticket reservation which I did on the name Karen Davis, can you assist?

ASSISTANT: Sure, we are here to help you.

USER: Ok, please change the dates of my existing reservation.

ASSISTANT: Ok, please give me a moment. Sorry, no reservation is available by your name.

USER: Ok, not a problem. Thank you for assisting me.

ASSISTANT: Thank you for availing our services.