You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

USER: Amy Johnson here. I want to change my reservation, can you help me?

ASSISTANT: Sure, please wait for a minute.

USER: Ok, please be quick.

ASSISTANT: I could not find any reservation with your name in our database.

USER: Oh! That's sad to know. Anyways, thank you for checking.

ASSISTANT: Welcome.