Correct Jquery API for HTML5 video

<script type="text/javascript">
var myVideo=document.getElementById("video1");

function playPause()
{
if (myVideo.paused)
myVideo.play();
else
myVideo.pause();
}

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

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

function makeNormal()
{
myVideo.width=420;
}
</script>