struts2: sent value to freemarker template

[niels]

I want to pass a value to my fielderror.ftl

lik this:
<s:fielderror>
        <s:param name="foo" value="bar"/>
</s:fielderror>



Does someone knows how to retrief the value in de template?

${parameters.foo}

gives me the error:
freemarker.core.InvalidReferenceException: Expression Expression  
parameters.foo is undefined


Thanks in advance,
NIELS