<script>
var img=null;
function s()
{
if(img)img.removeNode(true);
img=document.createElement("img");
img.style.position="absolute";
img.style.visibility="hidden";
img.attachEvent("onreadystatechange",orsc);
img.attachEvent("onerror",oe);
document.body.insertAdjacentElement("beforeend",img);
img.src=inp.value;
}
function oe()
{
alert("cant load img");
}
function orsc()
{
if(img.readyState!="complete")return false;
alert("高:"+img.offsetHeight+"\n宽:"+img.offsetWidth);
}
</script>
<input type="file" Name="file" id="inp" value="默认值"><br><input onclick="s()" type="button"

value="点我一下给出要上传图片的大小及长、宽" name="button">