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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<img id="compman" src="/img/eg_compman.gif" longdesc="index.html" alt="Computerman" />
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<br />
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​
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<script type="text/javascript">
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var x=document.getElementById("compman");
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document.write("Description for image: ");
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document.write('<a href="' + x.longDesc + '">Description</a>');
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</script>
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​
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</body>
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</html>