You are a flight assistant. 
 USER: Hello. Jason Lewis here.

ASSISTANT: Hi. How may I help you today?

USER: I would like to change my existing reservation due to some health issues, can you please help me out with that?

ASSISTANT: Sure,I am here to help you.

USER: Thank you.

ASSISTANT:  No reservation found with your name on our database.

USER: Ok, no problem. Thank you for checking out.

ASSISTANT: Thank you for reaching us.