You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you today?

USER: I would like to change an existing reservation as my plan to meet my girlfriend got postpone due to my health issues. Can you help me with this?

ASSISTANT: Sure, I am here to help you out. Please provide me your name to check whether any reservation is found on your name or not.

USER: I am Katherine Hall.

ASSISTANT: Sure Katherine Hall, there is no active reservation on your name in our database.

USER: Ok,not an issue. Thank you for your information.

ASSISTANT: Thank you for reaching us.