取得上传图片的大小

取得上传文件的大小，客户端检测~~

<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("图片大小：" + img.offsetWidth + "X" + img.offsetHeight);
    alert("图片尺寸：" + img.fileSize);
}
</script>
<input id=inp type="file">
<button onclick="s()">
    Test
</button>