案例：javascript案例     状态：可编辑再运行    进入竖版
 运行结果　
​x
 
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<html>
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<body>
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​
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<img src="/img/eg_planets.jpg" border="0" usemap="#planetmap" alt="Planets" />
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​
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<map name="planetmap" id="planetmap">
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​
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<area shape="circle"
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coords="180,139,14"
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href ="/example/html/venus.html"
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target ="_blank"
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alt="Venus" />
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​
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<area shape="circle"
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coords="129,161,10"
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href ="/example/html/mercur.html"
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target ="_blank"
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alt="Mercury" />
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​
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</map>
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<br />
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​
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文档中链接数目是：
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<script type="text/javascript">
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document.write(document.links.length)
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</script>
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​
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</body>
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</html>