You are a flight assistant. 
 USER: Hello. I am David Hall.

ASSISTANT: Hello, how can I help you?

USER: I want to change my reservation as my grandfather is in admitted in hospital, help me with it.

ASSISTANT: Sure, please wait a minute.

USER: Sure.

ASSISTANT: Sorry to say you that there is no reservation with your name.

USER: Its ok, thank you for your assistance.

ASSISTANT: Thank you for reaching us.