<script type="text/javascript"> //"text/javascript"，多了个j
var book = {};  //创建对象直接量，少了个 =
book.title="hello word";
book.chapter1 = new Object(); //创建新对象，Object()，大小写敏感
book.chapter1.title="hehe";
book.chapter1.pages=6;
book.chapter2={title:"qq",pages:6};
alert("title"+book.title+"\n\t"+"cp1"+book.chapter1.title+"\n\t"+"cp2"+book.chapter2.title);
</script>

------解决方案--------------------
正确写法：
<script type="text/javascript">
alert("测试开始!");
var book={};
book.title="hello word";
book.chapter1=new Object();
book.chapter1.title="hehe";
book.chapter1.pages=6;
book.chapter2={title:"qq",pages:6};
alert("title"+book.title+"\n\t"+"cp1"+book.chapter1.title+"\n\t"+"cp2"+book.chapter2.title);
</script>