解决layui调用自定义方法提示未定义的问题

layui.use(['layer', 'form', 'element'], function(){
 var layer = layui.layer
 ,form = layui.form
 ,element = layui.element
  function test(){
  //JS代码
  }
});

layui.use(['layer', 'form', 'element'], function(){
 var layer = layui.layer
 ,form = layui.form
 ,element = layui.element
  window.test = function(){
  //JS代码
  }
});