Accessing <input type="hidden" form fields

[jbeaken]

I am trying to access hidden POST data from a standard HTML form from seam:

<form name="searchCriteria" action="/search/criteria.seam" method="post">
     <input type="hidden" name="hiddenGenreSelection"  />
</form>

@RequestParameter

 @RequestParameter 
private String hiddenGenreSelection;

doesn't work maybe due to this being used only for GET request parameters.

Reverting to the servlet api :

          HttpServletRequest httpServletRequest = (HttpServletRequest) FacesContext.getCurrentInstance().getExternalContext().getRequest();
          Enumeration<String> enumeration = httpServletRequest.getParameterNames();
          while(enumeration.hasMoreElements()) {
               String name = enumeration.nextElement();
               log.debug("name #0 #1", name, httpServletRequest.getParameter(name));
          }

returns null as well, perhaps because the post data has already been read.

Is there I way to access POST data from a plain html form without using JSF or another view technology? My main issue is that a bespoke javascript tree writes to the form and I couldn't get javascript to write to a JSF form (that is populate a h:inputHidden) box. If anyone can tell me how to populate JSF components from javascript and have seam understand them, it would be much appreciated!

thanks!

[jbeaken]

Very simple really :

document.forms[0].elements[1].value = selectedGenresArr;

with jsf :

<h:form name="searchCriteria" action="/search/criteria.seam" method="post">
                                          <h:inputHidden id="genres" value="#{trackSearchCriteria.genresCSV}"/>