You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Due to my health conditions, I want to change my recent reservation.Can you help me with that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your name please?

USER: Susan White here.

ASSISTANT: Sorry to inform you that there is no active reservation on your given name.

USER: No problem, Thanks for the information.

ASSISTANT: Thanks for contacting us.