产品展示鼠标放上去显示上一个下一个的图标

图片：上一个：arr_left

下一个：arr_right

没找到在哪上传图片的呀

代码：<script>
function upNext(bigimg){
var lefturl = 'Sm_AnLi_Show.aspx?id=<%=PreId %>';
var righturl = 'Sm_AnLi_Show.aspx?id=<%=NextId %>';
var imgurl = righturl;
var width = bigimg.width;
var height = bigimg.height;
bigimg.onmousemove=function(){
if(event.offsetX<width/2){
bigimg.style.cursor = 'url(images/arr_left.cur),auto';
imgurl = lefturl;
}else{
bigimg.style.cursor = 'url(images/arr_right.cur),auto';
imgurl = righturl;
}
}
bigimg.onmouseup=function(){
top.location=imgurl;
}
}
</script>

显示的图片加属性： onmouseover="upNext(this)"