how to get selected drop down attribute value disply on in frontend?

$_product =Mage::getModel('catalog/product')->load($_product_ID);
                            echo $_product_s->getLength();
                            ======== OR ==========
                            echo  $_product_s->getAttributeText('length');
                            echo $_product->getResource()->getAttribute('length')
                             ->getFrontend()->getValue($_product);