You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I be your helping hand?

USER: I am Matthew Garcia, I need to change my reservation due to my brother is in hospital and I have to take care.

ASSISTANT: Sure, please wait for a while. Sorry there is no reservation found on your name.

USER: Thank you for the information.

ASSISTANT: Thank you for reaching us, take care.