ALWAYS use this glitch before a boss. First, make sure the item you want to duplicate is on the first right side panel or second panel (the panel is the place/on the top). Then make sure they are reuseable items, such as Elixrs,Potions, Antarctic wind. Then run around until you get into a battle. Then when you enter battle, go down to items. Then notice that when you press up it goes to the Attack option. Then go back to the item. Press Up+A at the same. Then if it works you will see a flash. Then make sure you don't go over 99. Also, you should do this with Antarctic Wind and sell them and get a lot of money! See ya'!