You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you out?

USER:  Due to some health issue, I am unable to travel now. Can you please change my existing reservation?

ASSISTANT: Sure, I will help you in changing the ticket. May I know your name please?

USER: Please check under the name Kenneth Allen.

ASSISTANT: Sorry, there are no reservations found.

USER: No issue, thank you.

ASSISTANT: Thank you for reaching us.