You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Emily Green.

ASSISTANT: What help are you expecting form our agency?

USER: I am planning to change an existing reservation, due to health issue. Can you please help me out?

ASSISTANT: Emily Green, please allow me to check with your previous booking.

USER: Sure.

ASSISTANT: I am very sorry to inform you, there is no active reservation found by your name in the reservation list.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you for contacting us.