Attaching Upload Function to a Callback

Should anyone else need to know, I've got this figured out. At least from the PHP Code side

-- File Upload - To Run custom code when a file is uploaded
open up the file:
/ckfinder/core/connector/php/php5/CommandHandler/FileUpload.php

if you want something to happen when a file uploads without a problem, look for the switch statement and add it within the case "UPLOAD_ERR_OK"

  switch ($uploadedFile['error']) {
            case UPLOAD_ERR_OK:
           
         // My Code
           if($_GET['type']=="Videos" || $_GET['type']=="Flash" ) {
            // Run Custom Code
         }
         
                break;

I wanted to prevent users from uploading files, to limit the # of uploaded files they can have.
So within FileUpload.php just before the switch statement I added the following, which when evaluates to
true it will throw an error, and ckfinder will stop processing the upload:

// My Code
      if(checkCreditsAvailable()) {
         $this->_errorHandler->throwError(CKFINDER_OUT_OF_CREDITS);
      }

-- Delete File custom code
open up the file:
/ckfinder/core/connector/php/php5/CommandHandler/DeleteFile.php

within the last if statement, where the bDeleted statement will be true add your code:

if ($bDeleted) {

             if($_GET['type']=="Videos" || $_GET['type']=="Flash" ) {
         // run some more custom code, when a file is deleted the # of files they can upload will increase

      }
}

I also set up the custom error message here:

-- To Create a Custom Error Message
open up the file:
ckfinder/core/connector/php/lang/en.php

Add an error to the array

'987' => 'You may not upload any more files.  Please purchase more credits.',

open up the file:
ckfinder/core/connector/php/constants.php

Add a global constant and match it to the # '987' of whatever you used in the step above.

define('CKFINDER_OUT_OF_CREDITS',987);