title: take attribute node and print distinct value using xslt
body: <pre><code>&lt;page&gt;
    &lt;tab dim="70"&gt;&lt;/tab&gt;
    &lt;tab dim="40"&gt;&lt;/tab&gt;
    &lt;tab dim="30"&gt;&lt;/tab&gt;
    &lt;tab dim="30"&gt;&lt;/tab&gt;
    &lt;tab dim="30"&gt;&lt;/tab&gt;
    &lt;tab dim="70"&gt;&lt;/tab&gt;
  &lt;/page&gt;
  </code></pre>
  
  <p>how to get the value of tab's dim attributes and take out the distinct value using xslt.means it will print 30,40,70</p>