// one hidden field per form:
String formHiddenFieldAttributeName = ATTRIBUTE_FUNCTION_NAME + formName;
if (cycle.getAttribute(formHiddenFieldAttributeName) == null)
{
body.addInitializationScript("document." + formName + "._linkSubmit.value = null;");
writer.beginEmpty("input");
writer.attribute("type", "hidden");
writer.attribute("name", "_linkSubmit");
cycle.setAttribute(formHiddenFieldAttributeName, this);
}