layer.open({
  content: 'test'
  ,btn: ['按钮一', '按钮二', '按钮三']
  ,yes: function(index, layero){
    //按钮【按钮一】的回调
  },btn2: function(index, layero){
    //按钮【按钮二】的回调
    return false;
  },btn3: function(index, layero){
    //按钮【按钮三】的回调
  }
  ,cancel: function(){ 
    //右上角关闭回调
  }
});