You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

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

ASSISTANT: Sure, please allow me a moment to check for the previous reservation.

USER: Ok.

ASSISTANT: Sharon, there is no reservation found under your name.

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

ASSISTANT: Thank you for contacting us.