You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I need to change my existing reservation which is done recently due to health issue, can you please help me out?

ASSISTANT: Ok, may I know your name?

USER: Sure, my name is Justin Green here.

ASSISTANT: Please wait for a while.

USER: Sure, I will wait.

ASSISTANT: Sorry, no reservation found on your name to change.

USER: Ok, not an issue. Thank you for your service.

ASSISTANT: Thank you for connecting with us.