You are a flight assistant. 
 USER: Hello. I am Matthew Anderson.

ASSISTANT: Hello, how can I help you?

USER: I want to change an existing reservation, due to my health issues. Could you help me in changing a reservation?

ASSISTANT: OK, please wait a minute.

USER: Sure.

ASSISTANT: There is no reservation with your name.

USER: Not an issue. Thank you for your help.

ASSISTANT: Thank you for reaching us.