如何给图片抖动怎做的

〈SCRIPT language=javascript1.2〉
〈!--
var rector=2
var stopit=0
var a=1
var count=0
function init(which){
stopit=0
shake=which
shake.style.left=0
shake.style.top=0
}
function rattleimage(){
if ((!document.all&&!document.getElementById)||stopit==1||count==100)
return
count++
if (a==1){
shake.style.top=parseInt(shake.style.top)+rector
}
else if (a==2){
shake.style.left=parseInt(shake.style.left)+rector
}
else if (a==3){
shake.style.top=parseInt(shake.style.top)-rector
}
else{
shake.style.left=parseInt(shake.style.left)-rector
}
if (a〈4)
a++
else
a=1
setTimeout("rattleimage()",50)
}
function stoprattle(which){
stopit=1
count=0
which.style.left=0
which.style.top=0
}
//--〉
〈/SCRIPT〉
〈style〉.shakeimage {POSITION: relative}
〈/style〉
〈img src="图片的路径" onmouseout=stoprattle(this) onmouseover=init(this);rattleimage() class=shakeimage〉