You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I oblige you today?

USER: I am Debra Lewis. I am volunteer in Blue tree environment, so I need to attend the event to expose my Power point presentation about trees to safe the environment. Due to some reasons, It has been postponed to some other day. Please help  me in changing my previous reservation?

ASSISTANT: Sure, that is what I am here. Please hold on a moment, I will check the previous reservation of your.

USER: Sure.

ASSISTANT: Thanks for waiting, no reservation was found by your name in our database.

USER: Thank you for your valuable information.

ASSISTANT: Thank you for reaching us.