Amnesia scripting!! Removing item ONLY if in inventory?

[AtraNox]

OnEnter()
{
SetEntityInteractionDisabled("ceremony_knife", true);
}

Thank you very much, this will be very useful! I couldn't find anything on the internet, so this will be helpful also to other people (i hope)!
Thank you again
P.S.: I'll put your name in the credits, my story will be called "Monsters", but I've just started so I need some time to finish it!