Problem getting new spells to work with items

How do you get a new spell effect to show up in WorldEd so that you can attach it to an item (like the mages staff)? I've made a new spell effect but it's not showing in the dropdown list.

 

If what you call a "new spell effect" was made by modifying "gameeffect" or "effect", you must know the game does not consider it spells. If you have coded your "spell effect", well, I have not the hell of an idea.