1、
<script>
document.Write("Hello wrrld!!!");
</script>
2、
<script language="javascript">
document.write("Hello World!!");
</script>
3、
<script language="JavaScript" type="text/JavaScript>
document.write("Hello World!!");
</script>
4、
<script language="JavaScript1.2">
document.writr("Helo World!!");
</script>
5、
<script src="hello.js"></script>
doxument.write("Hello World!!!")必须保存在hello.js外部文件里面