f</b> element evaluates an expression as a string,
 and outputs its value to the current output stream.
<p>The full syntax of expressions is given in <a href="expressions.html">XPath Expression Syntax</a>.
</p>

<p>The <b>select</b> attribute identifes the expression, and is mandatory.</p>

<p>The optional <b>disable-output-escaping</b> attribute may be set to "yes" or "no"; the default is
"no". If set to "yes", special characters such as "&lt;" and "&amp;" will be output as themselves,
not as enti