客户端检测文件大小

<script type="text/javascript">
function checkUploadedFilesSize(progressArea, args)
{
//progressArea.confirmed is a custom variable,
// you can use another if you want to
if (!progressArea.confirmed &&
args.get_progressData().RadUpload.RequestSize > 1000000)
{
if (confirm("The total size of the selected files" +
" is more than the limit." +
" Do you want to cancel the upload?"))
{
progressArea.cancelRequest();
}
else
{
progressArea.confirmed = "confirmed";
}
}
}
</script>
<telerik:RadUpload runat="server" id="RadUpload1" />
<telerik:RadProgressArea runat="server" id="RadProgressArea1"
OnClientProgressUpdating ="checkUploadedFilesSize" />
<telerik:RadProgressManager runat="server" id="RadProgressManager1" />
<asp:Button runat="server" id="Button1" text="Upload" />