You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you today?

USER: I need to modify my flight ticket booking due to some health issues and I am unable to travel on those dates, can you please help me with changing?

ASSISTANT: Sure, I am glad to help you with that.

USER: Thank you for accepting my request.

ASSISTANT: Could you send me your name?

USER: I have done the booking on my name Carol Evans.

ASSISTANT: Please wait for a minute.

USER: Sure, I can wait.

ASSISTANT: We are regret to inform you that, there is no active reservation on your name in our database.

USER: No problem, I think the ticket booking is not reserved properly while I was booking. Anyway thank you for your help.

ASSISTANT: Thank you for reaching us. Have a nice day.