AsyncFileUpload restrict file size to upload

Question

I am using AsyncFileUpload in order to allow users to asynchronously upload files.

I want to limit the size of the file to 1MB.

So far as to what I've seen I can only get the length of the file upon upload completion

like when upload starts:

(OnClientUploadStarted)

function UploadStarted(sender,args) 
{
   //if bigger than 1MB (approximately)
   if (args.get_length() > 1000000 ) 
   {
       ShowActionNotificationError( errorMessage); 
       return false;  
    }
}

args.get_length() is null , so I can't use it...

And when upload is completed:

(OnClientUploadComplete)

function UploadComplete(sender,args) 
{
    //if bigger than 1MB (approximately)
    if (args.get_length() > 1000000 ) 
    {
        ShowActionNotificationError( errorMessage); 
        return false;  
    }
}

works ok, but file was already uploaded...

So How can I know the size of the file before uploading it? am I missing something very simple?

I would really like to do it without handling HTTP Request length and the sort.

Thanks!

Answer 1

After some substantial research I realize this cannot be done using AJAX.

As I look around at sites like yahoo mail and gmail, it's done by Flash.

in hotmail it's done with Silverlight.

there is a free (for now) flash upload control called Uploadify...

I am now working on integrating it.

if I'm wrong please correct me! :)