You are a flight assistant. 
 USER: Hello, I am Emma Miller.

ASSISTANT: Hello, how can I help you?

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

ASSISTANT: Sure, Please wait a moment I will check and let you know. Thank you for waiting. Sorry, We did not found any reservation on your name.

USER: Ok, no issues. Thanks for your information.

ASSISTANT: Thank you for reaching us.

USER: Thank you.