HTML video播放如何使用dom控制呀？

<div style="text-align:center;">
<button onclick playPause()">播放/暂停</buttonz cbutton onclick=makeBig()">大-/buttons
<button onclick="makeNormal()">中</button> sbutton onclick="makeSmall()">小</button> sbr />
<video id "videol" width="420" style="margin-top:15px;">
<source src="/example/html5/mov_bbb.mp4 type="video/mp4" /><source src="/example/htm15/mov_bbb.ogg" type="video/ogg" /> Your browser does not support HTML5 video.</videos</div>
escript type="text/javascript">
var myVideo=document.getElementById("video1"):
function playPause(){
if(myVideo.paused) myVidea.play(); else
myVideo.pause();

function makeBig() myVideowidth=560;}
function makeSmall(){
myVideo.width=320

function makeNormal()
myVideo.width=420
</script>
</body>
</html>
这一段代码就可以实现video使用dom控制