title: How to show information in a table depending of the attribute value (XML-XSLT)
body: <p>I want to show the table with the values of the selected month in the dropdownlist, first i have the table hidden, with a function in javascript I show the table, now I don´t know how to show just the information relative to this month.
  could be with an if sentence in the xsl code? Thnks.</p>
  
  <p>books.xml </p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;?xml-stylesheet type="text/xsl" href="tabla.xsl"?&gt;
  &lt;TotalBooks&gt;
      &lt;books month= "January"&gt;
         &lt;book&gt;
           &lt;isbn&gt; 1 &lt;/isbn&gt;
           &lt;tittle&gt;The tittle&lt;/tittleo&gt;
           &lt;author&gt;Me&lt;/author&gt;
         &lt;/book&gt;
         &lt;book&gt;
           &lt;isbn&gt; 2 &lt;/isbn&gt;
           &lt;tittle&gt;The tittle two&lt;/tittleo&gt;
           &lt;author&gt;Me&lt;/author&gt;
         &lt;/book&gt;
      &lt;/books&gt;
  &lt;/TotalBooks&gt;
  </code></pre>
  
  <p>books.xsl</p>
  
  <p>
  </p>
  
  <p></p>
  
  <pre><code>&lt;html&gt;
    &lt;head&gt;
      &lt;script&gt;
        function TryOption() 
        { 
           tabla.style.visibility="visible";          
        }
  
      &lt;/script&gt;
    &lt;/head&gt;
    &lt;body&gt;
      &lt;h1&gt;My books&lt;/h1&gt;
      &lt;div&gt;
        &lt;label&gt; Sales/ month: &lt;/label&gt;
        &lt;select&gt;
          &lt;option&gt; &lt;/option&gt;
          &lt;xsl:for-each select="TotalBooks/books"&gt;
            &lt;option onclick="TryOption();"&gt;
              &lt;xsl:value-of select="@month"/&gt;
            &lt;/option&gt;
          &lt;/xsl:for-each&gt;
        &lt;/select&gt;
      &lt;/div&gt;
      &lt;div&gt;
        &lt;table id="tabla"&gt;
          &lt;tr bgcolor="skyblue"&gt;
            &lt;th align="left"&gt;Tittle&lt;/th&gt;
            &lt;th align="left"&gt;Author&lt;/th&gt;
          &lt;/tr&gt;
          &lt;xsl:for-each select="TotalBooks/books/book"&gt;
            &lt;tr&gt;
              &lt;td&gt;
                &lt;xsl:value-of select="tittle"/&gt;
              &lt;/td&gt;
              &lt;td&gt;
                &lt;xsl:value-of select="author"/&gt;
              &lt;/td&gt;
            &lt;/tr&gt;
          &lt;/xsl:for-each&gt;
        &lt;/table&gt;
      &lt;/div&gt;
    &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>
  </p>