protected void render(OutputData output) throws Exception {
if (viewSelector == null)
throw new RuntimeException("Widget '" + getClass().getName() + "' does not have a view selector!");
JspContext jspCtx = (JspContext) getEnvironment().getEntry(JspContext.class);
String jsp = jspCtx.getJspPath() + "/" + viewSelector + ".jsp";
ServletUtil.include(jsp, getEnvironment(), (ServletOutputData) output);
}