public function bindRequestParameters(ParameterBag $bag = null) {

		if($bag) {
			$this->requestValues = $bag;
		}

		else {
			if($this->request->getMethod() == 'GET') {
				$this->requestValues = $this->request->query;
			}
			else {
				$this->requestValues = $this->request->request;
			}
		}

		// set form element values

		foreach($this->elements as $name => $element) {
			if(is_array($element)) {
				$this->setElementArrayRequestValue($name);
			}
			else {
				$this->setElementRequestValue($element);
			}
		}

		return $this;
	}