addSubPart(btn_ok);
addSubPart(btn_cancel);
// create "Rename your Backpack" label at the top in the middle
int posX = xSize / 2 - fontRendererObj.getStringWidth(TITLE) / 2;
addSubPart(new Label(posX, 10, 0x000000, TITLE));
// create "New name:" label at the left site above the GuiTextField
addSubPart(new Label(20, 30, 0x404040, NEW_NAME));
// create text field
txt_backpackName = new Textbox(fontRendererObj, 20, 40, 200, 20);
txt_backpackName.setFocused(true);
txt_backpackName.setMaxStringLength(32);