请问如何用js获取图片大小？

Question

<SCRIPT language=javascript>
function index_image_valid(){
document.pho_up.indeximg.src=document.pho_up.pho_index.value;
imagewidth=document.pho_up.indeximg.width;
imageheigth=document.pho_up.indeximg.height;
alert ("宽："+imagewidth+"\n高:"+imageheigth);
}
</script>
</head>
<form name="pho_up" method="post" enctype="multipart/form-data">
<input type="file" name="pho_index" size="20" class=input Onchange="javascript:index_image_valid();"> 
<img name=indeximg>
</form>

Answer 1

<img src="csdn.gif" onclick="hehe(this)">
<script>
function hehe(m){
str='宽:'+m.offsetWidth+'\r\n高:'+m.offsetHeight
str+='\r\n大小:'+m.fileSize+'字节'
alert(str)
}
</script>

Answer 2

<img src=http://expert.csdn.net/images/csdn.gif border=0
 onload="alert('filesize : '+ fileSize +' Byte\r\nwidth  : '+ clientWidth + '\r\nheight : '+ clientHeight)">