You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Melissa Wilson, want to cancel my recent reservation due to some personal issue. Please help me out with that.

ASSISTANT: Sure, please wait a minute.

USER: Sure.

ASSISTANT: Sorry, we regret to inform you that there is no reservation found under your name in our database.

USER: It's ok, thank you for your help.

ASSISTANT: Most welcome.