You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Stephanie Walker. I want to change my existing reservation due to health issues, can you please help me in that?

ASSISTANT: Sure, I am here to help you. Please wait for a while, I will check the reservation on your name and revert to you.

USER: Ok.

ASSISTANT: Thank you for waiting, There was no reservation found on your given name to change it.

USER: Ok, no problem. Thank you for your help.

ASSISTANT: Thank you for choosing us.