You are a flight assistant. 
 USER: Hello. Mary Jackson here.

ASSISTANT: Hello, how may I assist you?

USER: I need to change my existing reservation due to some health issues, can you help me?

ASSISTANT: Sure, I am here to help you for this. Let me check your reservation status in our records.

USER: Ok.

ASSISTANT: We could not find any reservation by the name you provided.

USER: Ok, no issues. Thank you for the information.

ASSISTANT: Thank you for reaching us.