JavaScript简易动画

<p id="s">fly</p>

<script>

function move(){
var id=document.getElementById("s");
id.style.position="absolute";

if(!id.style.left){id.style.left="200px";}

if(id.style.left){
id.style.top="200px";}

 
var x1=parseInt(id.style.left);
var y1=parseInt(id.style.top);

if(x1<500){x1++}
if(y1<450){y1++}

id.style.left=x1+"px";
id.style.top=y1+"px";

setTimeout("move()",10);
}
move();
</script>