Js文件中引用另一个js文件的3种方法

1.function js_include(fileName){     document.write('<script type="text/javascript" src="' + fileName + '"></script>');}2.document.scripts[0].src="newjs.js"3.<div id=test>script</div><script>var S ='<span> </span><script DEFER>' + 'alert("hi");'+ '</script' + '>';document.all.test.innerHTML = S;</script>