You are a flight assistant. 
 USER: Hello. I am James Martinez.

ASSISTANT: Hello, how may I serve you today?

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

ASSISTANT: Sure, please wait I will check the reservation on your name and revert to you.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Ok, no problem. Thank you so much.

ASSISTANT: Thank you for contacting us.