Best Practices For Stopping The Uploading Process

When users upload files, there is a limit to the total storage that each user has. I have to check this every time the File Uploaded event occurs, because the same user could be uploading files from 2 (or more) different machines. So there is a database check to check the size of the file on every file upload. I need to stop the process if the next file that is uploaded will exceed this limit. I am not sure how to do this on the server side. How can I detect when the limit is reached in the server side asp.net vb code, and then tell the client to stop the process?

And I do not see a corresponding FileUploaded event on the client, so I think there may not be a way to do this. How do I stop the server side code in FileUploaded, and call some event on the client that calls RemoveAllFromUploadList and then alerts the user to the problem. Or should I try to do this on the server code somehow? If so, how do I do this when I do not see a RemoveAllFromUploadList method, and I am not sure if I can pop up an alert.

And then I could set a flag in the server vb.net code if the storage limitation is exceed and stop the uploading of the files, but it would be great to somehow remove the rest of the files in the list. What is the way to do this. And then I was thinking I could set a flag if this has a occurred, but I tried this, and the javascript cannot read the variable. Example?

Please answer all variations of this if you can. Thank you!

Edited by user Monday, March 15, 2010 8:07:25 PM(UTC)  | Reason: Not specified

OK, I need to alter this process a bit. I have the PackageComplete event working as described below.

However, I allow the user to upload many files at once. On the server side, I determine if a given file is too large to go beyond the user's storage space. At that point, on the server side, in the FileUploaded event, I can determine if the files is too large and I can send the response Response.Write("Failed") as you suggested.

However, I do not want the user to have to wait until the file is completely uploaded first for this to happen. If the user uploads a 100MB file, all that time would incur uploading the file for the user just to find out that the space is not available.

Is there an event to use to trap this process server side WHILE THE FILES ARE UPLOADING, not in the FileUploaded event? Isn't the file already uploaded at that point when it reaches the FileUploaded event (I know it is just in the asp.net temp cache at this point).

And then if I can pick up the bytes of the file server side before it uploads, I am not sure what to do. I looked at the OnClientPackageBeforeUpload event, but that does not have the ResponsePage parameter, so I have no idea how I would stop the uploading from happening.

If the above is possible, I would like to take this a step further. It would be great to tell the user that a file has been reached that is too large, but ask the user if he/she would like to continue uploading the rest of the files (because some of the files might be smaller and might not go beyond the storage space). Do you have some thoughts or sample code on that?