window.onload = function(){var a = document.getElementByTagName('video');var b = a.src;a.src = "广告地址";a.play();for(;;){if(a.currentTime===a.duration){a.src = b;break;}}}
唯一的缺点是,执行for循环会导致写在他后面的其他js代码不可以执行