You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: Unfortunately, I want to change my reservation due to some health issues, can you please help me in this condition?

ASSISTANT: Sure, I will help you. may I know your name to check the records?

USER: Sure, my name is Jacob Lewis here.

ASSISTANT: I am sorry Jacob Lewis, I can not help you with your concern, because there no reservation found on your name.

USER: Not an issue.

ASSISTANT: Thank you for choosing our agency.

USER: You are welcome.