You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Donna Jones here.

ASSISTANT: How may I assist you?

USER: Due to sudden health issue, I am not able to travel in a flight on those date that I want to travel. So, I would like to change my reservation. Can you please help me out with that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please wait a moment, I will check the status of your reservation.

USER: Sure, take your time.

ASSISTANT: Donna Jones, no reservation has been found on your name in our records.

USER: Oh! Not an issue. Anyway, thank you for the information.

ASSISTANT: Thank you for approaching us.

USER: Welcome.