    protected ModelAndView onSubmit(HttpServletRequest request,
            HttpServletResponse response, Object command, BindException errors)
            throws Exception {
		User user = ControllerUtil.getSignedInUser();
    	AddProjectParameters params = (AddProjectParameters) command;
    	ModelAndView modelAndView = null;
    	Projectcode projectcode = new Projectcode(params.getProjectcode());
    	try {
    		studentService.addStudentToRun(user, projectcode);
    		modelAndView = new ModelAndView(getSuccessView());
    	} catch (ObjectNotFoundException e) {
    		errors.rejectValue("projectcode", "error.illegal-projectcode");
    		return showForm(request, response, errors);
    	} catch (PeriodNotFoundException e) {
    		errors.rejectValue("projectcode", "error.illegal-projectcode");
    		return showForm(request, response, errors);
    	} catch (StudentUserAlreadyAssociatedWithRunException se) {
    		errors.rejectValue("projectcode", "error.student-already-associated-with-run");
    		return showForm(request, response, errors);
    	}
		return modelAndView;
    }

    protected synchronized ModelAndView onSubmit(HttpServletRequest request,
            HttpServletResponse response, Object command, BindException errors)
            throws Exception {
		User user = ControllerUtil.getSignedInUser();
    	AddProjectParameters params = (AddProjectParameters) command;
    	ModelAndView modelAndView = null;
    	Projectcode projectcode = new Projectcode(params.getProjectcode());
    	try {
    		studentService.addStudentToRun(user, projectcode);
    		modelAndView = new ModelAndView(getSuccessView());
    	} catch (ObjectNotFoundException e) {
    		errors.rejectValue("projectcode", "error.illegal-projectcode");
    		return showForm(request, response, errors);
    	} catch (PeriodNotFoundException e) {
    		errors.rejectValue("projectcode", "error.illegal-projectcode");
    		return showForm(request, response, errors);
    	} catch (StudentUserAlreadyAssociatedWithRunException se) {
    		errors.rejectValue("projectcode", "error.student-already-associated-with-run");
    		return showForm(request, response, errors);
    	}
		return modelAndView;
    }
