如何校验上传附件大小，急！！！

[jackeyfan]

我想在提交表单时检测，上传的附件大小，不知可否通过JavaScript来实现

[bailou]

[Objext Error]

[jeweldbs]

function getFileSize(){
var filename = document.all('F_File').value;
if(filename == '')
{
return false;
}
try {
var stream = new ActiveXObject('ADODB.Stream');
stream.Type = 1;
stream.Open();
stream.LoadFromFile(filename);
F_Size.value =stream.size;
}
catch(e) {
return false;
}return true;
}
<INPUT size='45' type='file' name='F_File' value='' onFocus='this.select()' onchange='getFileSize()'>