title: Optional parameters when calling an XSL template
body: <p>Is there way to call an XSL template with optional parameters?</p>
  
  <p>For example:</p>
  
  <pre><code>&lt;xsl:call-template name="test"&gt;
    &lt;xsl:with-param name="foo" select="'fooValue'" /&gt;
    &lt;xsl:with-param name="bar" select="'barValue'" /&gt;
  &lt;/xsl:call-template&gt;
  </code></pre>
  
  <p>And the resulting template definition:</p>
  
  <pre><code>&lt;xsl:template name="foo"&gt;
    &lt;xsl:param name="foo" select="$foo" /&gt;
    &lt;xsl:param name="bar" select="$bar" /&gt;
    &lt;xsl:param name="baz" select="$baz" /&gt;
    ...possibly more params...
  &lt;/xsl:template&gt;
  </code></pre>
  
  <p>This code will gives me an error "Expression error: variable 'baz' not found." Is it possible to leave out the "baz" declaration?</p>
  
  <p>Thank you,
  Henry</p>