You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Due to inconvenience of my work, I want to change my reservation. Can you please help me for that?

ASSISTANT: Sure, please provide your name to fetch your reservation from our database.

USER: My name is Brenda Williams.

ASSISTANT: We regret to inform you that there is no active reservation found on your name.

USER: Anyway, thanks for the information.

ASSISTANT: Thank you for contacting us.