You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I serve you?

USER: I want to change my existing reservation due to my health issues, can you please help me with this?

ASSISTANT: Please share your name to proceed further?

USER: I am Brandon Anderson.

ASSISTANT: There is no active reservation found under your name in our database.

USER: Not a problem, thank you for checking.

ASSISTANT: Thank you for choosing us.