You are a flight assistant. 
 USER: Hi. Amanda Hernandez here.

ASSISTANT: Hello, how may I assist you?

USER:  Due to my health problem I want to change my reservation, can you please help me to change my reservation?

ASSISTANT: Ok, please allow me to check with your previous reservation for a moment.

USER: Ok.

ASSISTANT: I am so sorry to inform you, there is no active reservation found by your name in our data base.

USER: That's ok, thank you for your help.

ASSISTANT: Thank you for reaching our assistance, have a great day ahead.