public static Block demoDoorBlock;
    public static Item demoDoorItem;

    @EventHandler
    public void preInit(FMLPreInitializationEvent event)
    {
        if (Loader.isModLoaded("malisisdoors"))
        {
            //Instantiate your descriptor
            DemoDoor demoDoor = new DemoDoor();
            demoDoor.create();
            demoDoorBlock = demoDoor.getBlock();
            demoDoorItem = demoDoor.getItem();
        }
        else
        {
            demoDoorBlock = new DemoDoorBlock();
            demoDoorItem = new DemoDoorItem();

        }
        demoDoorBlock.setBlockName(...).setHardness(...).setBlockTextureName(...).setStepSound(...);
        demoDoorItem.setUnlocalizedName(...).setTextureName(...).setCreativeTab(...);
        GameRegistry.registerBlock(demoDoorBlock, demoDoorBlock.getUnlocalizedName().substring(5));
        GameRegistry.registerItem(demoDoorItem, demoDoorItem.getUnlocalizedName());
        GameRegistry.addRecipe(new ItemStack(demoDoorItem), new Object[] { "AC", "BB", "CA", 'A', Items.ender_pearl, 'B',
                Items.iron_ingot, 'C', Blocks.planks });
    }