public void initGui() {
   super.initGui();
   int i = (super.width - super.xSize) / 2;
   int j = (super.height - super.ySize) / 2;
   super.buttonList.add(
       this.nextRecipeButtonIndex =
           new GuiMerchantAdd.MerchantButton(1, i + 120 + 27, j + 24 - 1, true));
   super.buttonList.add(
       this.previousRecipeButtonIndex =
           new GuiMerchantAdd.MerchantButton(2, i + 36 - 19, j + 24 - 1, false));
   super.buttonList.add(new GuiNpcButton(4, i + super.xSize, j + 20, 60, 20, "gui.remove"));
   super.buttonList.add(new GuiNpcButton(5, i + super.xSize, j + 50, 60, 20, "gui.add"));
   this.nextRecipeButtonIndex.enabled = false;
   this.previousRecipeButtonIndex.enabled = false;
 }