You are a flight assistant. 
 USER: Hello, I am Kathleen Perez.

ASSISTANT: Hello, how may I aid you?

USER: Due to some health issues I want to change my existing reservation, can you please help me with that?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

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

USER: Ok, no issues.

ASSISTANT: Thank you for choosing us.

USER: Thanks for your information.