鼠标指向漂浮中的图片后，图片静止，怎么加静止代码？

Question

<div  id="img"   onmouseover="clearInterval(interval)" onmouseout="interval = setInterval('changePos()', delay)" align="middle">
<a href="#" ></a><br><span class="reset" onclick="clearInterval(interval);img.style.visibility = 'hidden'">关闭 X</span>
</div>
<script type="text/javascript"> 
var xPos=300; 
var yPos=200; 
var step=1; 
var delay=16; 
var height=0; 
var Hoffset=0; 
var Woffset=0; 
var yon=0; 
var xon=0; 
var pause=false; 
var interval; 
changePos("img") ;

function changePos(objName) 
{ 

var thediv=document.getElementById(objName);
thediv.style.position="absolute";
thediv.style.left=parseInt(window.screen.availWidth*Math.random()) + "px";
thediv.style.top=parseInt(window.screen.availHeight*Math.random()) + "px";
thediv.setAttribute("xDir",1);
thediv.setAttribute("yDir",1);
window.setInterval("randPosition(" + objName + ")","18","JavaScript");
}

function randPosition(obj)
{
var x=parseInt(obj.style.left);
if(x>=1500)
obj.setAttribute("xDir",-1);
if(x<=0)
obj.setAttribute("xDir",1);
x+=parseInt(obj.getAttribute("xDir"));

var y=parseInt(obj.style.top);
if(y>=700)
obj.setAttribute("yDir",-1);
if(y<=0)
obj.setAttribute("yDir",1);
y+=parseInt(obj.getAttribute("yDir"));

obj.style.left=x +"px";
obj.style.top =y +"px";
}
function start() {
img.style.visibility  = "visible";
interval = setInterval('changePos()', delay);
}
start();


</script >

Answer 1

<div id="img" style="position: absolute; left: 2px; top: 43px;visibility :visible;"
      onmouseover="clearInterval(interval)" 
     onmouseout="start()" align="middle">
    <a href="#"></a><br><span class="reset" onclick="clearInterval(interval);img.style.visibility = 'hidden'">关闭 X</span>
</div>
<script type="text/javascript">
    var xPos = 300;
    var yPos = 200;
    var step = 1;
    var delay = 1000;
    var height = 0;
    var Hoffset = 0;
    var Woffset = 0;
    var yon = 0;
    var xon = 0;
    var pause = false;
    var interval;
    changePos("img");

    function changePos(objName) {

        var thediv = document.getElementById(objName);
        thediv.style.position = "absolute";
        thediv.style.left = parseInt(window.screen.availWidth * Math.random()) + "px";
        thediv.style.top = parseInt(window.screen.availHeight * Math.random()) + "px";
        thediv.setAttribute("xDir", 1);
        thediv.setAttribute("yDir", 1);
        //不要这句，要不没次执行都会起动新计时器了
        //interval = window.setInterval("randPosition('" + objName + "')", "18", "JavaScript");
    }

    function randPosition(obj) {
        var x = parseInt(obj.style.left);
        if (x >= 1500)
            obj.setAttribute("xDir", -1);
        if (x <= 0)
            obj.setAttribute("xDir", 1);
        x += parseInt(obj.getAttribute("xDir"));

        var y = parseInt(obj.style.top);
        if (y >= 700)
            obj.setAttribute("yDir", -1);
        if (y <= 0)
            obj.setAttribute("yDir", 1);
        y += parseInt(obj.getAttribute("yDir"));

        obj.style.left = x + "px";
        obj.style.top = y + "px";
    }
    function start() {
        img.style.visibility = "visible";
        interval = setInterval('changePos("img")', delay);
    }
    start();


</script>