javascript 监测(控制 )下传文件大小

javascript 监测(控制 )上传文件大小

<script language="javascript">var oForm = new Object();var oImage = new Image();oImage.attachEvent('onload',getSize);oImage.attachEvent('onerror',doWithError);function checkImage(obj){    oForm = obj;    oImage.src = oForm.oFile.value;}function getSize(){    var oImgSize = Math.floor(oImage.fileSize/1024);    if(oImgSize>200){        window.alert('不允许上传大于200KB的图片！');        oForm.reset();    }}function doWithError(){    window.alert('出现错误：请重新选择图片上传！');    oForm.reset();}</script>

<form name="data_form" method="post" enctype="multipart/form-data">    <input type="file" name="oFile" onpropertychange="javascript:checkImage(document.data_form);"></form>