javascript 实时 预览 上传时 缩略图

<script type="text/javaScript">
function FileChange(Value){
document.all.uploadimage.width=10;
document.all.uploadimage.height=10;
document.all.uploadimage.alt="";
document.all.uploadimage.src=Value;
}
</script>
<INPUT style="WIDTH: 143px; HEIGHT: 18px" type=file size=8 name=pic onchange="javascript:FileChange(this.value);">
<IMG id=uploadimage height=10 width=10 src="" ><BR>
<Button onclick="javascript:BeforeUpLoad();">提交</Button>