title: How to change attributes in fo:* elements
body: <p>I would like to transform a xml file into a xsl-fo to produce a pdf file. My problem is that some attributes are to be taken from the input xml, for example:</p>
  
  <pre><code> &lt;page width="210mm" height="297mm" /&gt;
  </code></pre>
  
  <p>and I would like to put with and height attributes inside:
      
  in place of page-width and page-height attributes value. I tried unsuccesfully some ways, using a xsl variable:</p>
  
  <pre><code>&lt;fo:simple-page-master master-name="pageMaster"
  page-height="$height" page-width="$with" margin="2cm"&gt;
  </code></pre>
  
  <p>or xsl:value-of</p>
  
  <pre><code>&lt;fo:simple-page-master master-name="pageMaster"
  page-height=&lt;xsl:value-of select="$height"/&gt;
  page-width=&lt;xsl:value-of select="$with"/&gt; margin="2cm"&gt; 
  </code></pre>
  
  <p>None of the above achieve any result as transform process stops with an error indicating some kind of sintax error.
  What's wrong? How can I do?</p>